الانتقال من المتوسط نموذج تحديد الهوية

التكلس بيئة جافة تشكل التربة التي تؤدي إلى تراكم كربونات الكالسيوم في طبقات التربة السطحية. كالسيت المعدنية تتكون من كربونات الكالسيوم. المعادن المشتركة الموجودة في الحجر الجيري. مجمع كربونات الكالسيوم يتكون من الكالسيوم والكربونات. كربونات الكالسيوم له التركيب الكيميائي التالي كاكو 3. كالديرا كآبة دائرية كبيرة في بركان. بركان كالديرا نوع من البركان المتفجر الذي يترك اكتئاب دائري كبير. بعض هذه الاكتئاب يمكن أن تكون كبيرة مثل 40 كيلومترا في القطر. هذه البراكين تشكل عندما الصخور الجرانيتية الرطب بسرعة ترتفع إلى سطح الأرض. كاليتش تراكم كربونات الكالسيوم عند سطح التربة أو بالقرب منه. السعرات الحرارية كمية الطاقة. يساوي كمية الحرارة المطلوبة لرفع 1 غرام من الماء النقي من 14.5 إلى 15.5 درجة مئوية عند الضغط الجوي القياسي. كالفينغ فقدان الكتلة الجليدية عندما ينهار الجليد إلى جسم مائي كبير مثل المحيط أو البحيرة. الفترة الكمبودية الجيولوجية التي وقعت من 570 إلى 505 مليون سنة مضت. وخلال هذه الفترة، تصبح اللافقاريات شائعة في المحيطات، وتشكل بورجيس شيل. انفجار الكمبري تنويع كبير من أشكال الحياة متعددة الخلايا في محيطات الأرض التي بدأت خلال الكمبري حوالي 570 مليون سنة مضت. الكندي ارتفاع ضغط النظام الذي يتطور في فصل الشتاء فوق وسط أمريكا الشمالية. الدرع الكندية القديمة جدا الصخرية والدروع المتحولة الصخور التي تغطي الكثير من شمال كندا. أنشئت قبل أكثر من سنتين إلى ثلاثة مليارات سنة. النظام الكندي لتصنيف التربة نظام هرمي يستخدم في كندا لتصنيف التربة. هذا النظام لديه خمسة مستويات: النظام. مجموعة كبيرة. مجموعة فرعية. أسرة . وسلسلة. على مستوى النظام، يتم التعرف على تسعة أنواع من التربة: برونيسول. تشيرنوزم. كريوسول. غليسول. لوفيسول. عضوي . بودزول. ريجوسول. و سولونيتزيك. الستارة بالتنقيط إعادة توجيه نسبة من المطر أو الثلج تسقط على النبات إلى حافة المظلة. الوادي وادي شديد الانحدار حيث عمق أكبر بكثير من العرض. هذه الميزات هي نتيجة لتعرية تيار. العمل الشعري حركة المياه على طول القنوات المجهرية. هذه الحركة هي نتيجة لقوتين: التصاق وامتصاص الماء إلى جدران القنوات وتماسك جزيئات الماء لبعضها البعض. المياه الشعرية الشعرية التي تتحرك أفقيا وعموديا في التربة من خلال عملية العمل الشعري. هذه المياه متاحة للاستخدام النباتي. الكربوهيدرات هو مركب عضوي يتكون من ذرات الكربون والأكسجين والهيدروجين. بعض الأمثلة هي السكريات. نشاء . والسليلوز. مركب كربونات يتكون من ذرة واحدة من الكربون وثلاث ذرات من الأكسجين. كربونات له التركيب الكيميائي التالية كو 3. الكربنة هو شكل من أشكال التجوية الكيميائية حيث تتفاعل أيونات كربونات وبيكربونات مع المعادن التي تحتوي على الكالسيوم والمغنيسيوم والبوتاسيوم والصوديوم. دورة الكربون التخزين والحركة الدورية للأشكال العضوية وغير العضوية من الكربون بين المحيط الحيوي. الغلاف الصخري. الغلاف المائي. والغلاف الجوي. ثاني أكسيد الكربون الغاز المشترك وجدت في الغلاف الجوي. لديه القدرة على امتصاص انتقائي الإشعاع في الفرقة الموجة الطويلة. هذا الامتصاص يسبب تأثير الاحتباس الحراري. وقد ازداد تركيز هذا الغاز باطراد في الغلاف الجوي على مدى القرون الثلاثة الماضية بسبب حرق الوقود الأحفوري وإزالة الأحراج وتغير استخدام الأراضي. ويعتقد بعض العلماء أن تركيزات أعلى من ثاني أكسيد الكربون وغازات الدفيئة الأخرى سوف تؤدي إلى تعزيز تأثير الاحتباس الحراري والاحترار العالمي. الصيغة الكيميائية لثاني أكسيد الكربون هي ثاني أكسيد الكربون. أول أكسيد الكربون غاز عديم اللون والرائحة وغير المذاق ينتج عن حرق الوقود الأحفوري غير المكتمل. الصيغة الكيماوية لأول أكسيد الكربون هي نقاط الكاردينال (كو كاردينال بوينتس) تم العثور على الاتجاهات الملاحية الرئيسية الأربعة (الشمالية، الشرقية، الجنوبية، والغربية) على بوصلة أو خريطة. آكلة اللحوم الكائنات الحية التغذوية التي تستهلك الحيوانات الحية أو أجزاء الحيوانات الحية للأغذية. ومن أمثلة الحيوانات آكلة اللحوم الأسد والفهود والفهود والضفادع والثعابين والصقور والعناكب. ويمكن أيضا أن يسمى كارينور المستهلك الثانوي أو المستهلك العالي. انظر أيضا الحيوانات العاشبة. detritivore. زبال. و آكلة اللحوم. قدرة الحمل (K) الحد الأقصى لحجم السكان من نوع واحد يمكن لموئل معين أن يدعمه. رسم الخرائط مجال المعرفة التي تدرس خريطة البناء. فعل إنشاء خريطة. نظام المتتالية T هو نظام حيث أننا مهتمون في المقام الأول في تدفق الطاقة أندور المسألة من عنصر واحد إلى آخر وفهم العمليات التي تسبب هذه الحركة. في نظام متتابع، نحن لا نفهم تماما العلاقات الكمية التي توجد بين العناصر المتعلقة بنقل الطاقة و أندور المسألة. الكارثة نظرية عامة تشير إلى أن بعض الظواهر على الأرض هي نتيجة لأحداث كارثية. على سبيل المثال، الفيضانات الكتابية هي المسؤولة عن تشكيلات الصخور الرسوبية وانقراض الديناصورات. كاتيون أيون يحمل تهمة الذرية إيجابية. التبادل الكاتيوني التبادل الكيميائي للكاتيونات بين معادن التربة والمواد العضوية مع محلول التربة وجذور النباتات. قدرة التبادل الكاتيونية قدرة التربة على تبادل الكاتيونات مع محلول التربة. وكثيرا ما تستخدم كمقياس للخصوبة المحتملة للتربة. كهف تجويف طبيعي أو عطل يتم وضعه بشكل أفقي تقريبا على سطح الأرض. التجويف عملية التآكل الشديد بسبب انهيار سطح فقاعات الهواء وجدت في التدفقات السريعة المقيدة من المياه. يسبب انفصال المواد من السطح. الخلية الخلية هي أصغر وحدة تعمل ذاتيا موجودة في الكائنات الحية. كل خلية محاطة بغشاء خارجي أو جدار يحتوي على مادة وراثية (دنا) وأجزاء أخرى للقيام بوظائف حياتها. بعض الكائنات الحية مثل البكتيريا تتكون من خلية واحدة فقط، ولكن معظم الكائنات الحية الموجودة على الأرض تتكون من خلايا كثيرة. الخلوية تتألف من الخلايا. عملية تحدث بين أو داخل الخلايا. السليلوز نوع من الكربوهيدرات. المكون الأساسي المستخدم في بناء جدران الخلايا النباتية. مقياس درجة مئوية لقياس درجة الحرارة. في هذا النطاق، يغلي الماء في 100deg وتجمد في 0deg. عصر الجيولوجيا سينوزويك التي وقعت من قبل 65 مليون سنة إلى اليوم. سينترال فنت الطريق الرئيسي الذي تمر به الصهارة البركانية إلى سطح الأرض. قوة القوة سنتريبتال المطلوبة للحفاظ على كائن تتحرك في نمط دائري حول مركز دوران. هذه القوة موجهة نحو مركز الدوران. شائعة في ظواهر الأرصاد الجوية مثل الأعاصير والأعاصير. C الأفق الأفقي الأفقي عادة ما يقع أسفل الأفق B وفوق الأفق R. وتتكون هذه الطبقة من الأساس المتجانس التي لم تتأثر بشكل كبير من عمليات توليد الطاقة. تفاعل السلسلة (نووي) عدد كبير من الانصهار النووي. التي تحدث داخل كتلة معينة من النظائر الانشطارية، التي تطلق كمية كبيرة من الطاقة في وقت قصير. الطباشير شكل من الحجر الجيري. وتتكون هذه الصخور الرسوبية من قذائف وهياكل عظمية من الكائنات الحية الدقيقة البحرية. تشابارال نوع من النباتات النباتية المشتركة في مناطق العالم التي لديها مناخ البحر الأبيض المتوسط ​​(على سبيل المثال، كاليفورنيا وإيطاليا). وتتميز الشجيرات. والأشجار الصغيرة التي تتكيف مع الظروف الجافة الموسمية. أيضا، اتصل اتصل، البحر ابيض المتوسط، سكروبلاند. تشيلات المواد العضوية التي تسبب عملية كيميائية من تشيلاتيون. تشيلاتيون عملية التجوية الكيميائية التي تنطوي على استخراج أو الكاتيونات المعدنية من الصخور والمعادن التي تشيلاتس. الكيميائية واحدة من الملايين من العناصر المختلفة والمركبات وجدت بشكل طبيعي وتوليفها من قبل البشر. الكائن الكيميائي أوتوتروف الذي يستخدم الطاقة الخارجية الموجودة في المركبات الكيميائية لإنتاج جزيئات الطعام. العملية المستخدمة لإنتاج الغذاء من قبل هذه الكائنات يعرف باسم الكيميائي. الطاقة الكيميائية الطاقة المستهلكة أو المنتجة في التفاعلات الكيميائية. التفاعل الكيميائي التفاعل بين المواد الكيميائية عندما يكون هناك تغيير في التركيب الكيميائي للعناصر أو المركبات المعنية. التجسيم الكيميائي انهيار الصخور والمعادن في جزيئات صغيرة الحجم من خلال التحلل الكيميائي. عملية التخليق الكيميائي التي تستخرج فيها الكائنات الحية العضوية المحددة مركبات غير عضوية من بيئتها وتحولها إلى مركبات مغذيات عضوية دون استخدام أشعة الشمس. انظر أيضا التمثيل الضوئي. تشرنوزم التربة (1) ترتيب التربة (نوع) من النظام الكندي لتصنيف التربة. هذه التربة شائعة على المروج الكندية. (2) نوع التربة الموجودة عادة في بيئات المراعي. وغالبا ما تكون هذه التربة سوداء اللون ولها أفاق متطورة غنية بالدبال. شينوك الرياح اسم الرياح أمريكا الشمالية التي تحدث على الجانب ليوارد من الجبال. هذه الرياح دافئة ولها رطوبة منخفضة. مركبات الكربون الكلوروفلوروكربونية (كفكس) هو غاز تم إنشاؤه بصورة مصطنعة أصبح مركزا في الغلاف الجوي للأرض. يتم إطلاق غازات الاحتباس الحراري القوية جدا من بخاخات الأيروسول، المبردات، وإنتاج الرغاوي. الصيغة الكيميائية الأساسية للكلوروفلوروكربونات هي سف x كل x. كلوروفيل الصباغ الأخضر وجدت في النباتات وبعض البكتيريا المستخدمة لالتقاط الطاقة في الضوء من خلال التمثيل الضوئي. كلوروبلاست أورغانيل في خلية تحتوي على الكلوروفيل وتنتج الطاقة العضوية من خلال التمثيل الضوئي. كروموسوم بنية العضوية التي تحمل الكائن الجيني كود (دنا). سيندر، البركان، أداة تعريف إنجليزية غير معروفة، الجزء الضيق من الظهر، بركان. بين 100 و 400 متر، تتكون من صخور انفجرت انفجرت من تنفيس مركزي بسرعة عالية. هذه البراكين تتطور من الصهارة من البازلتية إلى تكوين وسيطة. دائرة الإضاءة خط يقسم المناطق على الأرض التي تستقبل أشعة الشمس وتلك المناطق في الظلام. تقطع الأرض الكروية إلى نصفين مضاءين ومظلمين. سيركوم-باسيفيك بيلت منطقة تدور حول حافة حوض المحيط الهادئ حيث يسبب الانصهار التكتوني تشكيل البراكين والخنادق. وتسمى أيضا حلقة النار. سيرك، غلاسيالي، تآكل تآكل، إهتز، الحوض، أسس، عن، الجبال. وتنشأ معظم الأنهار الجليدية في جبال الألب من سيرك. سيرك، المجلدة، الجزء الضيق من الظهر، المجلدة، ذلك، بشق انفس، الاحتلال، أداة تعريف إنجليزية غير معروفة، سيرك. الغيوم سيركومولوس سحابة بيضاء مرتفعة الارتفاع تتكون من بلورات الثلج. وجدت في نطاق ارتفاع من 5،000 إلى 18،000 متر. سيروستراتوس الغيوم ورقة علو مرتفع مثل الغيوم تتكون من بلورات الثلج. هذه الغيوم رقيقة غالبا ما تغطي السماء بأكملها. وجدت في نطاق ارتفاع من 5،000 إلى 18،000 متر. غيوم السحب سحابة علو عال تتألف من بلورات الثلج. ظهور هذه الغيوم هو ريشة بيضاء مثل بقع، خيوط أو العصابات رقيقة. وجدت في نطاق ارتفاع من 5،000 إلى 18،000 متر. التصنيف عملية تجميع الأشياء في فئات. الصخور الرسوبية الرملية الصخور الرسوبية التي تتكون من تزييف الحطام الصخري المتجدد الذي تم نقله وإيداعه جسديا. الطين الجسيمات المعدنية مع حجم أقل من 0.004 ملليمتر في القطر. انظر أيضا الطمي والرمال. الانقسام ميل بعض المعادن أو الصخور لكسر على طول طائرات الضعف. ويحدث هذا الضعف بسبب طبيعة الروابط بين الحبوب المعدنية. جرف منحدر صخري أداة تعريف إنجليزية غير معروفة، شاهق، إنتقع، مشروع كليماب البحثي المتعدد التخصصات الذي أعاد بناء مناخ الأرض على مدى السنوات المليون الماضية من خلال فحص البيانات الوسيطة من النوى الرواسب المحيطية. المناخ النمط العام للظروف المناخية للمنطقة على مدى فترة زمنية طويلة (30 سنة على الأقل). المناخ الأمثل أحر فترة خلال عصر الهولوسين. وتتراوح هذه الفترة من حوالي 5000 إلى 3000 قبل الميلاد. خلال هذا الوقت كان متوسط ​​درجات الحرارة العالمية 1 إلى 2 درجة مئوية أكثر دفئا مما هي عليه اليوم. علم المناخ دراسة علمية لمناخ الأرض على مدى فترة طويلة تمتد (أكبر من عدة أيام). قد تشمل أيضا التحقيق في تأثير المناخ على البيئة الحيوية وغير الحيوية. مجتمع ذروة المجتمع النباتي الذي لم يعد يخضع لتغييرات في تكوين الأنواع بسبب الخلافة. رسم تخطيطي رسم بياني ثنائي الأبعاد يقوم بتخطيط درجة حرارة الهواء للمواقع وهطول الأمطار على فترات زمنية تتراوح من 24 ساعة إلى سنة. استنساخ (1) مجموعة من النباتات المماثلة وراثيا التي نشأت عن التكاثر الخضري الجنيني من أحد الوالدين. (2) النسخ المتماثل للفرد الذي يتطابق وراثيا مع والده. نظام مغلق هو نظام نقل الطاقة. ولكن لا يهم. عبر حدودها إلى البيئة المحيطة بها. وكثيرا ما ينظر كوكبنا كنظام مغلق. مغلق تاليك هو شكل من أشكال الأرض غير المجمدة المترجمة (تاليك) في منطقة من التجمد. وهو مغلق تماما من قبل التجمد في جميع الاتجاهات. سحابة مجموعة من الجزيئات الصغيرة من الماء السائل أو الصلب التي تحدث فوق سطح الأرض. وتصنف الغيوم وفقا لارتفاع حدوثها وشكلها. وتشمل أنواع الغيوم الرئيسية: سيروس. سيروكومولوس. سيروستراتوس. ألتوكومولوس. ألتوستراتوس. نيمبوستراتوس. ستراتوكومولوس. ستراتوس. الركام. و كومولونيمبوس. الفحم الصخور الرسوبية تتكون من بقايا مضغوط، ليثيفيد وتغيير النباتات. الفحم هو خليط صلب قابل للاحتراق من المركبات العضوية، الهيدروكربونات، مع 30 إلى 98 من الكربون بالوزن، مختلطة مع كميات مختلفة من الماء وكميات صغيرة من مركبات الكبريت والنيتروجين. وهي تتشكل في عدة مراحل حيث تتعرض بقايا النباتات للحرارة والضغط على مدى ملايين السنين. عملية التجميد حيث تنحدر قطرتان قطراتان أو أكثر معا في قطرة أكبر واحدة بسبب الاصطدام بالوسط. كثيب الرمل.، كثيب الرمل.، ذلك، النماذج، إلى داخل، ساحلي، أرياس. يتم توفير الرمال لتشكيلها من الشاطئ. موطن الأراضي الرطبة الساحلية الأراضي الرطبة وجدت على طول الساحل وتغطي مع المياه المالحة المحيطات لجميع أو جزء من السنة. وتشمل أمثلة هذا النوع من الموائل المستنقعات المد والجزر والبحيرات وشقق المد والجزر ومستنقعات المنغروف. المنطقة الساحلية نسبيا الجزء الغني بالمغذيات، الضحلة من المحيط الذي يمتد من علامة المد العالي على الأرض إلى حافة الجرف القاري. خط الساحل الخط الذي يفصل سطح الأرض عن المحيط أو البحر. معامل التقدير الإحصائي الذي يقيس نسبة التغير في المتغير التابع المرتبط بالانحدار الإحصائي لمتغير مستقل. يمكن حسابها عن طريق أخذ مربع إذا كان معامل الارتباط. كوفولوتيون التطور المنسق لنوعين أو أكثر يتفاعلون ويمارسون ضغوطا انتقائية على بعضهم البعض والتي يمكن أن تتسبب في خضوع كل نوع للتكيفات المرتبطة به. انظر أيضا التطور والانتقاء الطبيعي. كول السرج مثل الاكتئاب وجدت بين قمم الجبال اثنين. شكلت عندما اثنين من السيرك الجليدية المتعارضة مرة أخرى تآكل أريسيركت. صحراء الصحراء الباردة وجدت في خطوط العرض العالية وعلى ارتفاعات عالية حيث هطول الأمطار منخفضة. درجات حرارة الهواء السطحية باردة عموما في هذه البيئات الجافة. الجبهة الباردة منطقة انتقالية في الغلاف الجوي حيث تقدم كتلة الهواء البارد تشريد كتلة الهواء الدافئ. الجليد الجليدي البارد الذي يوجد فيه الجليد الموجود من سطحه إلى القاعدة لديه درجة حرارة باردة مثل -30 درجة مئوية على مدار السنة. وهذا أقل بكثير من نقطة انصهار الضغط. يمكن أن يسبب ذوبان الضغط ذوبان الجليد في قاعدة هذه الأنهار الجليدية. واحد من ثلاثة أنواع من الأنهار الجليدية: الجليد الجليدي المعتدل البارد والجليدية القطبية. الاستعمار حركة الأفراد أو انتشار الأنواع إلى إقليم جديد. المذنب كتلة كبيرة من الجليد والغبار التي لديها مدار حول نجم. التآزر التفاعل البيولوجي بين نوعين حيث يستفيد أحد الأنواع من حيث اللياقة البدنية في حين أن تجارب أخرى لا تؤثر على اللياقة البدنية. المجتمع يشير إلى جميع السكان من الأنواع المتفاعلة الموجودة في منطقة معينة أو منطقة معينة في وقت معين. حدود المجتمع الحيز المكاني لمجتمع فريد من نوعه. البوصلة أداة الملاحة التي تستخدم المجال المغناطيسي للأرض لتحديد الاتجاه. التفاعل بين المنافسة حيث يتطلب كائنان أو أكثر في نفس المساحة نفس المورد (مثل الغذاء والماء ومساحة التعشيش والمساحة الأرضية) وهو ما يحد من الإمداد بالأشخاص الذين يسعون إليه. يمكن أن تحدث المنافسة على المستويات الحيوية بين الأنواع أو داخل الأنواع. وقد تكون المنافسة أيضا نتيجة عمليتين مختلفتين: الاستغلال أو التدخل. الاستبعاد التنافسي الوضع الذي لا يمكن فيه لأي نوعين متفاعلين من المنافسة أن يحتلا نفس المكان الأساسي نفسه إلى أجل غير مسمى بسبب محدودية الموارد. ونتیجة ھذه العملیة ھي الانقراض المحلي للأنواع التي ھي منافس أفقر. بركان بركان مركب تم إنشاؤه من طبقات بديلة من التدفقات والصخور انفجرت. ارتفاعها يتراوح بين 100 إلى 3،500 متر طويل القامة. الكيمياء من الصهارة من هذه البراكين هو متغير تماما تتراوح بين البازلت والجرانيت. المركبات النباتات من عائلة كومبوسيتاي (أستيراسي). الأمثلة الشائعة لهذه النباتات المزهرة هي الشوك، الهندباء، وعباد الشمس. مجمع المركب هو ذرات عناصر مختلفة انضمت معا. مساحة ملموسة الفضاء الجغرافي الفعلي في العالم الحقيقي. ويقارب الجغرافيون هذا المساحة عندما يحاولون تمثيله في نموذج أو خريطة. ويشار إلى هذا التقريب باسم الفضاء المجرد. التكثيف التغير في حالة المادة من البخار إلى السائل الذي يحدث مع التبريد. تستخدم عادة في الأرصاد الجوية عند مناقشة تشكيل الماء السائل من بخار. وتطلق هذه العملية الطاقة الحرارية الكامنة على البيئة. التكثيف نواة الجسيمات المجهرية من الغبار والدخان أو الملح الذي يسمح لتكثيف بخار الماء إلى قطرات الماء في الغلاف الجوي. نوكليوس، ب، تشكيل، بسبب، أداة تعريف إنجليزية غير معروفة، إنهمر، دروب. يحدث التكثيف عادة على هذه الجزيئات عندما تصبح الرطوبة النسبية 100. بعض نواتج التكثيف، مثل الملح، هي استرطابية والماء يمكن أن تتكثف عليها في الرطوبة النسبية أقل من 100. التوصيل التوصيل يتكون من نقل الطاقة مباشرة من الذرة إلى الذرة ويمثل تدفق الطاقة على طول التدرج درجة الحرارة. مخروط الاكتئاب مخروط شكل الاكتئاب التي تحدث أفقيا عبر طاولة المياه. أسباب الإزالة المفرطة للمياه الجوفية بئر سطحية. طبقة المياه الجوفية المحصورة بين طبقتين من مواد أرضية غير منفذة نسبيا، مثل الطين أو الصخر الزيتي. المياه الجوفية المحصورة تم تجميع المياه الجوفية بين طبقتين من الصخور. التكتل الصخور الرسوبية الحبيبية الخشنة المكونة من شظايا صخرية مدورة مثبتة في خليط من الطين والطمي. النباتات الصنوبرية الغطاء النباتي المخروط من خطوط العرض الوسطى والعالية التي هي في معظمها دائمة الخضرة والتي لها شكل الإبرة أو مقياس مثل الأوراق. مقارنة مع النباتات النفضية. بيولوجيا الحفظ العلوم المتعددة التخصصات التي تتعامل مع الحفاظ على الجينات. محيط . مجتمعات . والنظم الإيكولوجية التي تشكل التنوع البيولوجي للأرض. وهي تحقق عموما الآثار البشرية على التنوع البيولوجي وتحاول وضع نهج عملية للحفاظ على التنوع البيولوجي والسلامة الإيكولوجية. المستهلك الكائن الحي الذي يتلقى المواد الغذائية (الغذاء) اللازمة للصيانة والنمو، والتكاثر من استهلاك أنسجة المنتجين أندور المستهلكين الآخرين. تسمى أيضا غير تغاير. وقد تم الاعتراف العديد من أنواع مختلفة من المستهلكين بما في ذلك: آكلات اللحوم. حيوانات آكلة اللحوم ونباتات . الزبالين. آكلة الأعشاب . ديتريتيفوريس. والمستهلكين الثانويين. والمستهلكين من الدرجة الثالثة. كونتاكت ميتامورفيسم هو تغيير متحول على نطاق صغير من الصخور بسبب التدفئة المترجمة. وعادة ما يكون السبب عن طريق التسلل البخاري مثل عتبة أو السد. القاري القطب الشمالي الكتلة الجوية (أ) كتلة الهواء التي تشكل على مساحات واسعة من اليابسة في خطوط العرض العالية. وفي نصف الكرة الشمالي، لا يشكل هذا النظام إلا في فصل الشتاء فوق غرينلاند وشمال كندا وشمال سيبيريا وحوض القطب الشمالي. الكتل الهوائية القارية القطبية الباردة جدا وجافة للغاية. هذه الكتلة الهوائية هي أيضا مستقرة جدا. القشرة القارية الجرانيتية جزء من قشرة الأرض التي تشكل القارات. ويتراوح سمك القشرة القارية بين 20 و 75 كيلومترا. انظر طبقة سيال. القاع القاري المنطقة المرتفعة التي تحدث في قارة تفصل أحواض الصرف القاري. نظرية الانجراف القاري التي تشير إلى أن قشرة الأرض تتكون من عدة لوحات قارية لديها القدرة على التحرك. أول من اقترحها A. سنيدر في 1858 والتي وضعتها F. B. تايلور (1908) وألفريد فيجنر (1915). التأثير القاري تأثير السطوح القارية على مناخ المواقع أو المناطق. ينتج عن هذا التأثير نطاق أكبر في درجة حرارة الهواء السطحية على المستويين اليومي والسنوي. انظر أيضا التأثير البحري. القاري الجليدي أكبر نوع من الجليدية مع تغطية سطحية في حدود 5 ملايين كيلومتر مربع. ورقة الجليد القارية انظر القارية الجليدية القارية. الهوامش القارية المنطقة الواقعة بين شاطئ القارات وبداية قاع المحيط. ويشمل الجرف القاري. القاري. والمنحدر القاري. كونتيننتال بلات شريحة صلبة ومستقلة من الغلاف الصخري تتكون أساسا من الجرانيت الذي يطفو على الغلاف الوهمي البلاستيك اللزج ويتحرك فوق سطح الأرض. وتبلغ مساحة لوحات الأرض القارية 125 كيلومترا في المتوسط ​​وتشكلت منذ أكثر من 3 مليارات سنة. انظر أيضا لوحة المحيطات. القاري الكتلي الكتلة الجوية (كب) الكتلة الهوائية التي تشكل على مساحات واسعة من اليابسة من خطوط العرض المتوسطة إلى العالية. في أمريكا الشمالية، شكل النظام في شمال كندا. الكتل القارية القطبية الهواء باردة وجافة جدا في فصل الشتاء وباردة وجافة في فصل الصيف. هذه الكتلة الهوائية هي أيضا مستقرة في الغلاف الجوي في كلا الموسمين. قاري الارتفاع طبقات سميكة من الرواسب وجدت بين المنحدر القاري في قاع المحيط. الجرف القاري الهامش المغمور الضحلة للقارات الواقعة بين حافة الشاطئ والمنحدر القاري. وتتكون هذه المساحة شبه القشرية من القشرة القارية من طبقات سطحية تتكون من رواسب أو صخور رسوبية. الجرف القاري استراحة منطقة الحدود بين الجرف القاري والمنحدر. الدرع القاري انظر الدرع. المنحدر القاري يوجد جزء مائل من القشرة القارية بين الجرف القاري والارتفاع القاري. الكتلة القارية الاستوائية القارية (كت) الكتلة الهوائية التي تشكل مناطق واسعة من اليابسة في خطوط العرض المنخفضة. في أمريكا الشمالية، شكل هذا النظام على جنوب غرب الولايات المتحدة وشمال المكسيك. القاري كتل الهواء الاستوائية دافئة وجافة في فصل الشتاء والساخنة والجافة في فصل الصيف. هذه الكتلة الهوائية هي أيضا غير مستقرة عموما في فصل الشتاء ومستقرة في فصل الصيف. الخط (الخط) الخط على الخريطة الطوبوغرافية التي تربط جميع النقاط مع نفس الارتفاع. كونتور إنتيرفال الفرق في الارتفاع بين خطين كفافيين متتاليين. ويعتمد الفاصل الزمني الذي يتم فيه رسم الأكفة على الخريطة على مقدار الإنصاف المرسوم وحجم الخريطة. نظام التحكم نظام يتم التحكم فيه بذكاء من قبل أنشطة البشر. على سبيل المثال، سد على نهر. متجمد دائم الشكل من التجمد الموجود عبر المناظر الطبيعية كطبقة غير منقطعة. الحمل الحراري ينطوي على نقل الطاقة الحرارية عن طريق التحركات الكتلة الرأسية من خلال وسيلة. الحمل الحراري الحالي حركة الغاز أو السوائل في الفوضى الحركة العمودية الشامل بسبب التدفئة. رفع وظيفي رفع الرأسي للطرود من الهواء من خلال التدفئة الحمل الحراري للغلاف الجوي. هذه العملية يمكن أن تبدأ عمليات أدياباتيك داخل الطرود الجوية. هطول الأمطار وظيفية هو تشكيل هطول الأمطار بسبب تسخين السطح من الهواء على سطح الأرض. في حالة حدوث تسخين كاف، تصبح كتلة الهواء أكثر دفئا وأخف وزنا من الهواء في البيئة المحيطة بها، تماما مثل منطاد الهواء الساخن يبدأ في الارتفاع والتوسع والتبريد. عندما يحدث التبريد الكافي يحدث التشبع تشكيل هطول الأمطار. هذه العملية نشطة في المناطق الداخلية للقارات وبالقرب من خط الاستواء تشكيل الغيوم الركام والعواصف الرعدية المحتملة في وقت لاحق. وعادة ما يكون المطر هو نوع هطول الأمطار الذي يتم تشكيله، وفي معظم الحالات يتم تسليم هذه الرطوبة بكميات كبيرة على مدى فترات قصيرة من الزمن في المناطق المترجمة للغاية. التقارب تدفق أفقي من الرياح إلى منطقة. مرة واحدة في المنطقة، والرياح ثم يسافر عموديا. التقارب هطول الأمطار تشكيل هطول الأمطار بسبب التقارب بين اثنين من الجماهير الجوية. وفي معظم الحالات، يكون للكتلتين الجويتين خصائص مناخية مختلفة. واحد عادة ما يكون دافئا ورطبة، في حين أن الآخر هو بارد وجاف. الحافة الرائدة من الكتلة الهوائية الأخيرة بمثابة جدار يميل أو الجبهة مما يؤدي إلى رفع الهواء الدافئ الرطب. وبطبيعة الحال رفع يسبب كتلة الهواء الرطبة الدافئة لتبرد بسبب التوسع مما أدى إلى التشبع. هذا النوع من هطول الأمطار شائع في خطوط العرض الوسطى حيث تشكل الأعاصير على طول الجبهة القطبية. تسمى أيضا هطول أمامي. رفع التقارب الرفع الرأسي للطرود من الهواء من خلال التقارب بين كتل الهواء المتعارضة في الغلاف الجوي. هذه العملية يمكن أن تبدأ عمليات أدياباتيك داخل الطرود الجوية. التوقيت العالمي المنسق (أوتك) مرجع الوقت العالمي الرسمي الحالي للأغراض المدنية والعلمية. ويقاس التوقيت العالمي المنسق من ست ساعات ذرية قياسية في المكتب الدولي للأوزان والمقاييس (بيبم) في باريس، فرنسا. نفذت في عام 1964. الحيوانات البحرية المرجانية بسيطة التي تعيش تكافلي مع الطحالب. في العلاقة التكافلية، توفر الطحالب المرجان مع المغذيات، في حين أن المرجان توفر الطحالب مع هيكل للعيش فيه. تفرز الحيوانات المرجانية كربونات الكالسيوم لإنتاج الهيكل العظمي الخارجي الصلب. المرجان تبييض الحالة حيث المرجان تفقد الطحالب التكافلية الملونة. يعتقد أن المياه الدافئة غير المعتادة، والتغيرات في ملوحة مياه البحر في المحيطات. أو التعرض المفرط للأشعة فوق البنفسجية. الشعاب المرجانية ريدج من الحجر الجيري وجدت عموما تحت سطح المحيط. يتم إنتاج هذه الميزة البحرية من قبل العديد من المستعمرات من الحيوانات المرجانية الصغيرة، ودعا الاورام الحميدة، التي تخلق هياكل كربونات الكالسيوم حول أنفسهم للحماية. وعندما تموت الشعاب المرجانية، تشكل هياكلها الخارجية الشاغرة طبقات تسبب الشعاب في النمو. وتوجد الشعاب المرجانية في المناطق الساحلية من المحيطات المدارية وشبه الاستوائية الدافئة. الأساسية جوهر هو طبقة غنية بالحديد والنيكل وجدت في المناطق الداخلية من الأرض. وهو يتألف من اثنين من الطبقات الفرعية: النواة الداخلية والخارجية الأساسية. جوهر حوالي 7000 كيلومتر في القطر. كوريوليس فورس قوة واضحة بسبب دوران الأرض. أسباب تحريك الأجسام المتحركة إلى اليمين في نصف الكرة الشمالي وإلى اليسار في نصف الكرة الجنوبي. قوة كوريوليس غير موجود على خط الاستواء. وهذه القوة مسؤولة عن اتجاه التدفق في ظواهر الأرصاد الجوية مثل الأعاصير في منتصف خط العرض. الأعاصير. و أنتيكلونيس. معامل الارتباط الإحصائي الذي يقيس درجة الارتباط الخطي بين متغيرين. وتتراوح قيمه بين -1 و 1. الكمال الايجابي (المتغير التابع يزيد مع زيادة في المتغير المستقل) الارتباط الخطي له معامل ارتباط 1. الكمال السلبي (المتغير التابع ينقص مع زيادة المتغير المستقل) الخطية جمعية لها معامل ارتباط -1. على الإطلاق أي ارتباط بين المتغيرات له قيمة صفر. كولي (1) تدفق حاد من الحمم البركانية التي عززت. (2) قناة ملتوية جليدية مهجورة. (3) المصطلح المستخدم في الولايات المتحدة لوصف وادي تيار شديد الانحدار. إعادة توجيه الإشعاع المضاد للإشعاع الطويل الموجة للأرض إلى السطح بسبب تأثير الدفيئة. كراتون الأساسية الأساسية مستقرة من الأرض لوحات مختلفة من القشرة القارية. تتألف من الدرع ومنصة. كريتر الاكتئاب الدائري في سطح الأرض التي أنشأتها النشاط البركاني أو تأثير الكويكب. زحف (1) حركة كتلة بطيئة من التربة المنحدر. يحدث حيث الضغوط على المواد المنحدر صغيرة جدا لخلق الفشل السريع. انظر زحف التربة. (2) مصطلح آخر يستخدم لوصف الجر. العصر الطباشيري الفترة الجيولوجية التي وقعت ما يقرب من 65 إلى 144 مليون سنة مضت. خلال هذه الفترة، تظهر أول أنواع النباتات المزهرة والديناصورات هي في أعظم تنوعها. الديناصورات يموت في نهاية هذه الفترة. كريفاس (1) فتح على السد الذي يسمح لتصريف المياه من السهول الفيضية إلى قناة تيار. (2) كسر على سطح هش من النهر الجليدي. سرعة إنتراينمنت الحرجة السرعة المطلوبة لإدخال جسيمات حجم معين في وسط متحرك من الهواء أو الماء. قشرة الأرض الخارجي معظم طبقة من الصخور الصلبة. بين 7 إلى 70 كيلومترا سميكة. يوجد نوعان من القشرة: القشرة المحيطية والقشرة القارية. كريوسول سويل ترتيب التربة (النوع) من النظام الكندي لتصنيف التربة. هذه التربة هي شائعة في بيئات خطوط العرض عالية التندرا. والميزة الرئيسية التي تحدد هذه التربة هي طبقة من التربة الصقيعية على بعد متر واحد من سطح التربة. ضغط البرد الضغط تمارس على مادة من الجليد في بقية. كريوتيك شيء يتم تجميده. سحابة الركام منتفخ السحب مع قواعد مسطحة نسبيا. الغيوم الركام تشكل عندما رطبة فقاعات الهواء الدافئ الهروب عموديا من سطح الأرض. توجد في نطاق ارتفاع من 300 إلى 2000 متر. كومولونيمبوس كلاود سحابة عمودية متطورة جيدا غالبا ما يكون لها أعلى شكل مثل سندان. هذه الغيوم كثيفة جدا مع الماء المكثف والمودعة. الطقس المرتبطة بهذه السحابة تشمل: الرياح القوية حائل الأعاصير البرق الرعد والأمطار الغزيرة. عندما يحدث هذا الطقس هذه الغيوم ثم العواصف الرعدية. يمكن أن تمتد في الارتفاع من بضع مئات من الأمتار فوق السطح إلى أكثر من 12،000 متر. كوسبت فورلاند هو تراكم الثلاثي من الرمال أندور الحصى تقع على طول الساحل. يتم تشكيل هذه الميزة من خلال الانضمام من اثنين من البصاق. البكتيريا الزرقاء البكتيريا التي لديها القدرة على التمثيل الضوئي. سيكلوجينيسيس عملية تشكيل الأعاصير، النضج، والموت. إعصار منطقة الضغط المنخفض في الغلاف الجوي الذي يعرض حركة دائرية الداخل من الهواء. في الدورة الدموية في نصف الكرة الشمالي هو عكس اتجاه عقارب الساعة، في حين أن الأعاصير في نصف الكرة الجنوبي لديها أنماط الرياح في اتجاه عقارب الساعة. السيتوبلازم كل بروتوبلازم في خلية ما عدا ما يرد في النواة. الاقتباس: بيدويرني، M. (2006). كوتلوساري أوف تيرمز: ككوت. أساسيات الجغرافيا الفيزيائية، الطبعة الثانية. تاريخ المشاهدة. physgegeypyysgeoglosc. html تم إنشاؤها من قبل الدكتور مايكل بيدويرني سكوت جونز جامعة كولومبيا البريطانية أوكاناغان البريد الإلكتروني التصحيحات والاقتراحات إلى: كوبيرايت كوبي 1999-2008 مايكل بيدويرنيا متابعة دراسة الأطفال الذين بدأوا المدرسة في سن 4 (المشار إليها باسم السنة 1 في هذه الدراسة ) لدراسة تأثير ثلاثة نماذج ما قبل المدرسة المختلفة على نجاح المدرسة في وقت لاحق. تمت دراسة هؤلاء الأطفال من منطقة المدارس الحضرية مرة أخرى في السنة الخامسة وهم مستعدون لمغادرة الصفوف الابتدائية وفي السنة 6 عندما كان من المقرر أن يدخل الصف الرابع إذا لم يتم الاحتفاظ بها سابقا. ودرست الدراسة درجات بطاقات التقييم، ومعدلات الاستبقاء، ووضع التعليم الخاص ل 160 طفلا في نهاية سنتهم الخامسة في المدرسة و 183 طفلا في نهاية سنتهم السادسة في المدرسة. The sample was 96 African American and 54 female, with 75 of the children qualifying for subsidized school lunch and 73 living in single-parent families. Academically, girls surpassed boys at the end of Year 5, and this difference persisted into the next grade level. Children whose preschool experience was more academically directed had been retained less often than peers. No differences attributable to preschool model were found for special education placement. By the end of childrens fifth year in school, there were no significant differences in academic performance of children who had experienced three different preschool models. By the end of their sixth year in school, children whose preschool experiences had been academically directed earned significantly lower grades compared to children who had attended child-initiated preschool classes. Childrens later school success appears to have been enhanced by more active, child-initiated early learning experiences. Their progress may have been slowed by overly academic preschool experiences that introduced formalized learning experiences too early for most childrens developmental status. Introduction In the ongoing debate over education reform designed to improve academic performance of American children, preschools are under increasing pressure to offer instruction in basic academic skills. This trend is especially prevalent in programs that serve low-income children. Compensatory early childhood programs such as Head Start and state-sponsored pre-kindergarten for low-income families and preschoolers with special needs are designed to help children acquire skills needed for later school success. Although the goal of school readiness is widely shared among early childhood educators, parents, and policy makers, the strategies for achieving this goal vary greatly. Fundamental philosophical and political differences in beliefs about the purpose of schooling, value orientations, and cultural priorities are central to the debate on how to best prepare young children for formal schooling (Kessler, 1991). Kindergarten retention rates have increased (e. g. Shepard amp Smith, 1988), perhaps due to the downward shift in curriculum that introduces formal reading and mathematics instruction much earlier. Escalating academic demands in kindergarten have clearly affected preschool programs for even younger children. Goffin (1994) noted a downward movement of the debate between developmental and academic orientations from elementary education to the preschool setting. When preschool was quotreconceptualized as an appropriate beginning for primary schooling (especially for low-income children),quot public school programs for 4-year-olds grew in number (Goffin, 1994, p. 120). Beginning in the 1980s, leading early childhood experts expressed concern about the wisdom of overly didactic, formal instructional practices for young children (e. g. Elkind, 1986 Zigler, 1987). They feared that short-term academic gains would be offset by long-term stifling of childrens motivation and self-initiated learning. Later research suggests that these early concerns were warranted. Compared to children whose kindergarten experience emphasized child-initiated learning, primary-grade teachers rated children from didactic, teacher-centered kindergartens lower in conduct and work-study habits, and perceived them to be more distractible, less willing to follow directions, and less prosocial (Hart, Charlesworth, Burts, amp DeWolf, 1993). Stipek, Feiler, Daniels, and Milburn (1995) also found motivational differences favoring a child-initiated view of early education compared to a more formalized, didactic approach. They cautioned that early academic gains in reading skills associated with didactic instruction of preschoolers quotcome with some costsquot that could have long-term negative effects on achievement. DeVries, Reese-Learned, and Morgan (1991) expressed similar concerns, arguing that temporary benefits of highly didactic approaches with young children cannot be justified in light of possible negative consequences for social development. Today, as Walsh (1989) predicted, the likelihood that children will experience a highly didactic, teacher-centered approach has increased as preschool is absorbed into public schools where a narrowly focused, externally imposed curriculum makes the preschool experience even more like elementary school. Although it was once believed that any well-implemented preschool program would achieve positive results (e. g. Lazar, Darlington, Murray, Royce, amp Snipper, 1982), a growing research base suggests otherwise (see Marcon, 1999, for a review of research on different preschool approaches). Of particular interest in the present study was sustainability of an earlier preschool approachs influence on academic performance. Several researchers have found that later school success declined when the intervention was discontinued. For example, Miller and Dyer (1975) found a drop in school achievement for children who entered a nondidactic program following a direct instruction preschool experience. Similarly, when the highly didactic Direct Instructional System for the Teaching of Arithmetic and Reading (DISTAR) was discontinued after third grade, childrens previously high achievement in reading and mathematics declined (Becker amp Gersten, 1982). Early academic success fostered by a child-initiated approach has been documented by a number of different researchers (e. g. Burts, Hart, Charlesworth, amp DeWolf, 1993 Marcon, 1993, 1999 Weikart, Epstein, Schweinhart, amp Bond, 1978). Some long-term benefits of this approach have been found for school achievement (e. g. Miller amp Bizzell, 1984) as well as for social behavior and general school competence (e. g. Schweinhart amp Weikart, 1997 Schweinhart, Weikart, amp Larner, 1986). Little is known, however, about the long-term effect of early intervention that combines didactic, teacher-centered strategies with child-initiated learning experiences. In the short term, this combination approach has varying outcomes, with some research favoring the strategy, especially for lower functioning children (e. g. Mills, Dale, Cole, amp Jenkins, 1995). A preponderance of the research evidence, however, has failed to support the combination approach (e. g. DeVries et al. 1991 Marcon, 1999 Pfannenstiel amp Schattgen, 1997 Rawl amp OTuel, 1982). Knowing how later school success of these children compares with that of children exposed to other preschool models would be useful in determining the effectiveness of a combination strategy. A second area of interest in the present study involved sex differences in later school success. Academically, studies of low-income children have found that girls did better than boys in pre-kindergarten (e. g. Marcon, 1999), kindergarten (e. g. Burts et al. 1993 Marcon, 1993), and in first grade (e. g. Reynolds, 1989). Boys do notably better in both the short and long term when their early learning experiences have been more child initiated rather than more didactic in nature (e. g. Marcon, 1993 Miller amp Bizzell, 1984). Successful transition between grade levels may also be moderated by sex. Parents and principals believe boys have more difficulty than girls in making the transition from third to fourth grade (Mayfield, 1983). Furthermore, differences in school competence (especially rates of nonpromotion) among African American children may be intensified by negative attitudes and behaviors toward school exhibited as early as fourth grade by African American boys (Rowan, 1989). Further examination of sex differences in later school success of low-income children and possible interaction with preschool model would add to our understanding of the often difficult transition from the primary to the later elementary school grades. The present study provides follow-up data for one cohort of low-income, minority children who had attended two years of school (preschool and kindergarten) prior to entering first grade. These children had experienced one of three different types of preschool: child-initiated, academically directed, or a quotcombinationquot approach. In this earlier quasi-experimental study, Marcon (1999) compared the three different approaches for their effect on childrens development and mastery of basic skills at the end of preschool. Findings indicated that children whose preschool experiences had been child-initiated demonstrated greater mastery of basic skills at the end of preschool than did children in programs where academics were emphasized and skills were directly taught. At the end of preschool, children in the quotcombinationquot model did significantly poorer on all measures except self-help and development of social coping skills compared to children in either the child-initiated or academically directed models. Preschool girls outperformed boys in all areas except gross motor development and playleisure skills. This follow-up study examines the transition from childrens fifth to sixth year in school (third to fourth grade for most of these children). Based on earlier findings for these children and results of other research studies (e. g. Miller amp Bizzell, 1984 Schweinhart amp Weikart, 1997 Schweinhart, Weikart, amp Larner, 1986), it was thought that any difference in later school success attributable to preschool model would favor the child-initiated early learning approach. Children who had experienced quotcombinationquot preschool curricula were expected to be least successful, whereas later school performance of those who had attended didactic, teacher-centered preschools was expected to be intermediary. Sex differences in school achievement favoring girls were expected to persist because boys, in general, do not perform as well in the early years of school (Richardson, Koller, amp Katz, 1986), and African American boys, unlike boys in general, do not typically show a rise in school achievement following the elementary school years (Pollard, 1993). The type of preschool experience was expected to have a greater effect on later school achievement of boys than on girls. Participants Children who began school at age 4 (referred to as Year 1 in this study) were studied again in Year 5 (when they were expected to be in third grade if not previously retained) and Year 6 (when they were expected to be in fourth grade if not previously retained) of their educational experience. This sample of urban students included 160 Year 5 children ( M age 107.6 months, SD 3.9) in 61 schools and 183 Year 6 children ( M age 119.8 months, SD 3.6) in 70 schools. The initial sample had been randomly selected proportional to enrollment of 4-year-olds in subdistricts within the school system. Each subdistrict was represented by at least one classroom for each of the three models studied. This stratified sample was geographically dispersed across the city and was representative of socioeconomic, administrative, and local variations within the school system (see Marcon, 1992, for a description of random selection and stratification procedures used in the original cohort study). This follow-up sample from the original cohort was 96 African American and 54 female. Most children (75) qualified for subsidized school lunch based on low family income, and 73 of the children lived in single-parent families. Data from both Years 5 and 6 were available for a subsample of the children ( n 139) in 64 schools. Subsample children did not differ significantly from the larger follow-up sample in any demographic characteristics. Recovery rate from preschool to fourth grade was 64 of the original sample. Although this attrition rate was high, it was not unexpected, and attrition was comparable across the preschool models, (2) 1.80, p .41. The recovered follow-up sample was not significantly different from the original preschool sample in terms of gender ( p .92), age ( p .82), parent involvement ( p .34), overall adaptive behavior ( p .16), social and work habits ( p .23), or physical development ( p .15) in preschool. Preschool grades of children in the recovered follow-up sample were, however, 3 lower than the original sample ( p .02). Compared to the original preschool sample, the recovered follow-up sample had more African American and fewer White children, (3) 15.34, p .01, who were poorer, (1) 12.60, p lt .001, and more likely to live in single-parent families, (1) 4.83, p .03. These differences were consistent with school districtwide changes in enrollment patterns following pre-kindergarten and kindergarten when children of many middle-class families leave the public school system. At age 4, all children had attended free, full-school-day preschool in the same urban school district, with approximately 84 of the sample having been enrolled in pre-kindergarten and 16 in Head Start. Eligibility for pre-kindergarten was based solely on age and residency, whereas Head Start eligibility had an additional federal requirement of low family income. All preschool teachers of children in this study, both pre-kindergarten and Head Start, held a bachelors degree or higher. Their median pre-kindergarten or Head Start teaching experience was approximately 10 years. As previously classified (see quotMeasures and Proceduresquot section for details), approximately 33 of children in this follow-up sample had attended preschool classes that followed a child-initiated approach, 35 attended academically directed preschool classes, and the remaining 32 had been enrolled in middle-of-the-road preschool classes that combined the other two preschool approaches. No Head Start classes in this school district used an academically directed approach. Kindergarten in this school district was predominantly academic in focus, with all but a handful of teachers indicating a strong belief that academic preparation was a more important goal of kindergarten than childrens socioemotional growth (Marcon, 1990, 1993). All first-grade teachers in this school district emphasized academics, with approximately two-thirds using a highly didactic, academically directed approach (Marcon, 1990). Measures and Procedures Preschool Model. The Pre-K Survey of Beliefs and Practices (see Marcon, 1999, for instrument and details) was used to classify childrens early learning experiences based on five theoretical differences between early childhood models: (1) scope of developmental goals, (2) conception of how children learn, (3) amount of autonomy given to the child, (4) conception of teachers role, and (5) provision of possibilities for learning from peers. Three groupings identified through cluster analysis using Wards method were selected as examples of the divergent preschool models operating in this urban school system. One group was composed of child development-oriented teachers who facilitated learning by allowing children to actively direct the focus of their learning. These child-initiated preschool classrooms were referred to as Model CI. Another group represented more academically oriented teachers who preferred more direct instruction and teacher-directed learning experiences for preschoolers. These academically directed preschool classrooms were referred to as Model AD. The third group represented teachers whose beliefs and practices fell in between the other two opposing models by endorsing a combination approach. These middle-of-the-road preschool classrooms were referred to as Model M. In the original study, accuracy of model classification based upon survey response was affirmed by independent classroom observers, and findings were congruous with other research demonstrating strong consistency between outside raters observations of early childhood instructional activities and teachers self-reported beliefs and practices (e. g. Charlesworth, Hart, Burts, Mosley, amp Fleege, 1993 Hyson, Hirsch-Pasek, amp Rescorla,1990 Kagan amp Smith, 1988 Vartuli, 1999). In the original study, Model CI and Model AD classifications were easily verified by independent classroom observers, but these same observers had some difficulty categorizing Model M practices in several classrooms. Model M teachers appeared to be closer to Model CI in goals but more like Model AD in teacher initiation of activities. Compared to Model CI teachers, the Model M teacher was notably more engaged in leading groups of children in less-individualized activities for longer periods of time. Compared to Model AD teachers, the Model M teacher allowed children greater access to classroom materials, encouraged more peer interaction, and initiated fewer teacher-directed cognitive activities that were not well integrated with other developmental domains. These Model M teachers were not, however, using a Vygotskian approach to foster childrens early learning and development. Model M teachers were best described as professionals who sought to blend notions of child development with their school systems competency-based curriculum. Their basis for doing so was most likely pragmatic. Report Cards. Data were collected from teachers and school records at the end of Year 5 and Year 6. The school districts Elementary School Progress Report (report card) was used to compare childrens classroom performance with the districts expectations for skills mastery. Like many urban school districts, a competency-based curriculum (CBC) was in place throughout most of the school system, and children were expected to demonstrate mastery of specific reading and arithmetic skills before advancing to the next grade level. CBC defined a skill as being mastered when a child could perform it upon request and provided teachers with three mastery assessment tasks for each reading and arithmetic objective (see McClure amp Leigh, 1981, for details of this school systems CBC). For research purposes, Progress Report grades were converted to the standard 5-point numeric scale: 0 F, 1 D, 2 C, 3 B, and 4 A. Each childs overall grade point average (GPA) was calculated. Grades in each of 11 subject areas were also converted to numeric scores: arithmetic, reading, language, spelling, handwriting, social studies, science, art, music, healthphysical education (PE), and citizenship. Citizenship grades provided a global assessment of a childs deportment while attending school. School records and teacher report provided information on the childs eligibility for subsidized school lunch and the number of parents or guardians living at home with the child (scored as 1 or 2). School Competence: Special Education Placement and Retention Year 5. During the primary grades (first, second, and third grades), this school district was more inclined to use retention in grade rather than special education services for children who experienced academic difficulties. By Year 5, less than 1 of this random sample had received special education services, whereas 20 had been retained in grade. No significant differences in special education placement were found for preschool model or sex. Special education placement during the primary grades was not related to family income as measured by eligibility for subsidized school lunch ( p .44) or to the childs living in a single-parent family ( p .43). Boys were more likely to have been retained prior to Year 5 (34) than were girls (10), (1, N 161) 13.97, p lt .001. Similarly, teachers were likely to recommend more boys (23) than girls (11) for retention at the end of Year 5, (1, N 165) 4.28, p .04. Although no significant difference in retention rate attributable to preschool model was found for girls ( p .41), Model AD boys had a significantly lower rate of retention prior to third grade than did boys who had attended other types of preschool, (2, n 71) 7.20, p .03. Overall, fewer children who had attended Model AD preschools had been retained prior to third grade (10), (2, N 161) 5.50, p .06, compared to retention rates of 24 and 26 for Models CI and M, respectively. There were no significant differences attributable to preschool model in teachers recommendations for retention at the end of Year 5 ( p .75). Other demographic factors (family income, single-parent families) that could contribute to retention in grade were examined. Lower-income children were more likely than higher-income children to have been retained prior to third grade, (1, N 160) 7.02, p .01. Although no significant difference in retention rate at the end of Year 5 was found between children who did or did not qualify for subsidized lunch ( p .14), teachers recommended far fewer children who did not qualify for subsidized lunch for retention than was expected statistically. Children who lived in single-parent versus two-parent families did not differ in retention rates prior to Year 5 ( p .18). At the end of Year 5, however, teachers were somewhat less likely to recommend retention for children who were growing up in two-parent families, (1, N 133) 2.44, p .12. Year 6. Because children were of the age to be leaving the primary grades, this school district was now more inclined to recommend special education services for children who experienced academic difficulties, (1, N 139) 5.16, p .02. In Year 6, the number of children who received special education services increased to 8 of the sample. No significant differences in special education placement were found for preschool model or sex. Special education placement following the primary grades was somewhat related to family income, (1, N 166) 2.52, p .11. Only half as many children who did not qualify for subsidized lunch as expected statistically were receiving special education services. Special education placement in Year 6 was not related to growing up in a single-parent family ( p .31). Possibly due to increases in special education placement, teachers recommendations for retention at the end of Year 6 (10) decreased in comparison with retention recommendations made at the end of Year 5 (16). No significant differences were found in recommended retention at the end of Year 6 for preschool model, sex, or family income. Teachers were more likely to recommend children from single-parent families for retention at the end of Year 6 than children living in two-parent families, (1, N 149) 4.25, p .04. Year 5 Report Cards A 3 x 2 (Preschool Model x Sex) analysis of covariance (ANCOVA) was used to test for differential effects of preschool model on childrens grades, sex differences, and possible Preschool Model x Sex interactions at the end of Year 5 in school. The covariate used to control for possible economic differences between children was eligibility for subsidized school lunch (based on family income and size). Although a direct measure of family income would have been a more desirable covariate, it was not available. Eligibility for subsidized school lunch should be highly correlated with family income and is a widely used estimate of family income in public school evaluation research. All reported means have been adjusted for the covariate. Missing scores were not imputed. The academic performance of children who were quoton schedulequot at the end of Year 5 (third grade), as well as performance of children who had been retained prior to third grade, was examined in this follow-up study. Preschool Model. No significant main effect for preschool model was found in Year 5 overall GPA or any specific subject area for either quoton schedulequot or quotretainedquot children. A statistical trend toward significant differences between preschool models was found for Year 5 citizenship grades, F (2, 153) 2.66, p .07. Overall, Model AD children received citizenship grades that were 6 and 19 lower than Model CI and Model M children, respectively. Citizenship grades reflect childrens deportment in school. At the end of Year 5, children from the three different preschool models were performing academically at a comparable level. Teachers did, however, see the school behavior of children who had attended academically directed preschools as being notably poorer than that of peers. Sex Differences. A significant sex difference was found in overall Year 5 GPA, F (1, 153) 4.05, p .05, with girls earning a 10 higher GPA than boys. Effect size for this difference was moderate (.34). As seen in Figure 1, girls earned higher grades in each of the 11 subject areas. A significant difference was found for citizenship grades, F (1, 153) 12.26, p .001, with teachers rating girls school behavior 24 quotbetterquot than that of boys. Effect size for the difference in citizenship grades was large (.58). At the end of Year 5, girls were outperforming boys in school. Interactions. No significant Preschool Model x Sex interactions were found for overall GPA or any of the 11 subject areas for either quoton schedulequot or quotretainedquot children. No statistical trends toward significant group differences were found. The smallest gap between performance of boys and girls appeared for Model M children (boys GPA was only 2 lower than girls GPA). In four subject areas (language, spelling, art, and music), Model M boys received somewhat higher grades than did Model M girls. A similar pattern was not present in the other two preschool models. Year 5 Summary. For children who had attended preschool and kindergarten prior to entering first grade, there was no significant difference in academic performance attributable to preschool model at the end of childrens fifth year in school. Girls outperformed boys in school, but this difference was less noticeable among children who had attended quotcombinationquot preschool classes. Teachers rated boys school behavior lower than girls behavior. Compared to peers, children who had attended academically directed preschool classes also were rated lower in behavior compared to peers at the end of their fifth year in school. Year 6 Report Cards Preschool Models. As shown in Table 1 and Figure 2, a trend towards statistical significance between preschool models was found in Year 6 overall GPA ( p .07). GPA for Model CI was 4 higher than Model M and 14 higher than Model AD. The difference between Models CI and AD was moderate (effect size .38). In all subject areas except music, Model AD children displayed the lowest grades of the three preschool models. In all but three subject areas (language, social studies, and music), Model CI had the highest grades compared to peers who had other types of preschool experiences. Science grades of Model M children equaled those of Model CI. Post hoc Tukeys HSD ( p lt .01) indicated that Models CI and M earned significantly higher healthPE grades than did Model AD. By the end of Year 6, academic performance of children who had attended academically directed preschool classes was beginning to decline. Although not statistically significant, their school behavior continued to be rated somewhat lower than that of peers Model AD citizenship grades were 14 and 9 lower than Models CI and M, respectively. Table 1 Year 6 Report Cards: Preschool Model (PM) and Sex Differences (GB) Note: Means adjusted for family income (eligibility for subsidized lunch) covariate. Sex Differences. As shown in Table 1 and Figure 3, a significant sex difference was found in overall GPA ( p .003), with girls receiving 13 higher grades than boys. Effect size for this difference was moderate (.44). Girls earned higher grades in all of the 11 subject areas except art. These differences were statistically significant for reading, spelling, social studies, and citizenship. Effect sizes for sex differences were moderate to large, with the greatest effect size seen in citizenship grades (.76). A trend toward statistically significant differences between girls and boys was found in four other subject areas: arithmetic, language, science, and healthPE. At the end of Year 6, girls continued to outperform boys in school. Interactions. No significant Preschool Model x Sex interactions were found for overall GPA or any of the 11 subject areas in Year 6. A possible interaction between preschool model and sex was found for Year 6 music grades, F (2, 153) 2.59, p .08. Unlike other boys, Model AD boys earned somewhat higher grades in music (6) than did Model AD girls. However, at the end of childrens sixth year in school, the smallest gap between school performance of boys and girls appeared for Model CI children. The GPA of Model CI boys was only 9 lower than that of girls, whereas a 16 and 14 difference between girls and boys GPA was found for Models M and AD, respectively. Year 6 Summary. School performance of those who had attended academically directed preschool classes was beginning to decline by the end of childrens sixth year in school. Girls still outperformed boys in school, but this difference was now less noticeable among children who had attended child-initiated preschool classes. Teachers continued to rate school behavior of boys lower than that of girls. Although no significant differences attributable to preschool approach were found in behavior at the end of the sixth year in school, teachers continued to rate behavior of children with academically directed preschool experiences somewhat lower than their peers. Transition from Year 5 to Year 6 A 3 x 2 x 2 (Preschool Model x Sex x Year) repeated measures multiple analysis of covariance (MANCOVA) with year as the repeated variable was used to test for differential effects of preschool model on childrens grades, sex differences, and possible Preschool Model x Sex interactions across time (Year 5 to Year 6). As with previous analyses, the covariate used to control for possible influence of economic differences between children was eligibility for subsidized school lunch. Missing scores were not imputed. Main Effect for Year. Although childrens grades generally dropped as they left the primary grades and entered the later elementary school grades, no significant main effect for year was found in the subsamples overall GPA, F (1, 132) .88, p .35. Analyses of each subject area yielded only one significant main effect for year subsample childrens grades in language decreased 8 from Year 5 to Year 6, F (1, 131) 4.78, p .03. Effect size for this difference was small (.16). Interactions across Years. Of greater interest in childrens transition from the primary to the later elementary school grades was how an earlier preschool model or childrens sex or both might differentially affect school performance across years. Therefore, two-way interactions (Preschool Model x Year Sex x Year) and the possibility of a three-way interaction (Preschool Model x Sex x Year) were examined more closely. As shown in Table 2 and Figure 4, there was a significant interaction between preschool model and year for GPA ( p .02). The GPA of Model CI children increased 6, while GPA decreased 4 and 8 for Models M and AD, respectively. A similar pattern of Model CI increases and Models M and AD decreases was found in 6 of the 11 subject areas: reading, language, spelling, science, healthPE, and citizenship. In an additional three subject areas (arithmetic, art, and handwriting), Model CI grades either remained constant or increased. Model M grades increased in only one subject area, music. Model AD grades increased in only one subject area, handwriting. Finally, all three preschool models showed a drop in childrens social studies grades from Year 5 to Year 6. Table 2 ANCOVA Interactions for Preschool Model and Sex: Year 5 to Year 6 As shown in Table 2, four subject area Preschool Model x Year interactions were significant: arithmetic, reading, spelling, and healthPE. Statistical trends toward significant interactions were found for language and citizenship. Only one Sex x Year interaction was found to be significant. Girls grades in spelling increased 3, and boys grades decreased. A somewhat similar pattern was found for healthPE grades ( p .07), with boys grades decreasing 6 and girls grades remaining constant in healthPE. This Sex x Year interaction pattern, however, was not typical of other subject areas. Figure 5 shows increases or decreases in boys and girls grades across years for each preschool model. As seen in Table 2, citizenship was the only subject area to show a significant three-way interaction between preschool model, childrens sex, and year ( p .05). Model CI boys and girls had similar increases in citizenship grades across years (8 and 6, respectively). The overall decrease in Model M citizenship grades was due primarily to a 19 drop in boys grades Model M girls decreased only slightly (2). Citizenship grades of Model AD boys increased 26, while girls citizenship grades decreased 7. The source of boys improvement was due primarily to fewer failing Year 6 citizenship grades among boys whose school deportment had been previously unacceptable. Even with this improvement, however, Model AD boys remained 11 behind Model CI boys in Year 6 citizenship grades. And, although improved, these Year 6 citizenship grades for Model AD boys still remained lower than citizenship grades of girls (33, 32, and 18 lower compared to Models CI, M, and AD girls, respectively). Discussion As predicted, preschool model did have an influence on childrens later school achievement. Children whose preschool experience was child initiated faired better than peers in the transition from the primary to the later elementary school grades. Not only were their overall grades following the transition significantly higher, their school performance improved or held constant in all but two subject areas (music, social studies) despite increased academic demands of the next grade level. Contrary to predictions, children from preschool classes where teachers had attempted to combine distinctive approaches were performing better in school than expected. By the end of their fifth year in school, they had quotcaught upquot to classmates from other preschool models. Relative to peers, the position of children with combination approach preschool experiences was intermediary following the transition. Findings regarding later school success were somewhat mixed for children who had more didactic, academically directed preschool experiences. Although fewer of these children had been retained during the primary grades, children from this preschool model were least successful in making the transition to the later elementary school grades. Grades of children from academically directed preschool classrooms declined in all but one subject area (handwriting) following the Year 6 transition. What contributed to the lower rates of retention prior to third grade among children whose earlier preschool experiences had been academically directed One possibility is greater continuity between the preschool experience and what children encountered in this public schools kindergartens and primary grades. After preschool, these children were likely to enter a moderately academic kindergarten with more formal instruction practices in reading and arithmetic (Marcon, 1993). In fact, only 20 would have experienced a more socioemotional-oriented kindergarten in this school district, and virtually none of the first-grade classrooms that children entered would have resembled less academically focused preschools. Model AD children most likely had an easier transition to the primary grades. A second possibility involves family-related influences on early grade retention. Lower-income children in this follow-up study were more likely to have been retained prior to third grade. Children eligible for Head Start came from the lowest-income homes and in the setting of this study were likely to be growing up in single-parent families. No children eligible for Head Start in this study were enrolled in Model AD classes. Thus, lower retention of Model AD children could be more related to family income factors than to type of preschool experience. A third possibility is that grade-level placements may not fully reflect academic performance in a competency-based system of promotion that emphasizes basic reading and arithmetic skills. If mastery of critical skills in these two subjects was not demonstrated, children were automatically retained regardless of their performance in other subject areas. Likewise, children who demonstrated mastery of critical reading and arithmetic objectives were able to advance regardless of performance in other subject areas. Meeting basic competency requirements of the primary grades may not be sufficient to sustain later academic performance when quotpulling it all togetherquot requires more than just quotadding up the piecesquot children have acquired along the way. Children with academically directed preschool experiences may have missed out on the more integrative experiences of peers in other preschool models. Future research to investigate each of these possibilities is needed. By the end of the primary grades, there was little difference in the academic performance of children who had experienced three different preschool models. This finding was consistent with the developmental assumption that, by the end of third grade, most children will have attained the basic academic skills. Earlier limitations associated with a combination approach had been overcome, and children were generally academically comparable and on quoteven footingquot when they entered the transition to the later elementary school grades. What happened on the other side of this transition Why did academic performance of children from academically directed preschool classes begin to decline The difference between their school grades and those of children from child-initiated preschools was not just statistically significant151the 14 difference in grades was of practical significance with children differing by more than a third of a standard deviation in overall grades. Perhaps the answer can be found in new demands characteristic of the later elementary school grades. Through the primary grades, children are learning to read. An academically directed approach typically emphasizes the act of reading over comprehension. Beginning in fourth grade, children are reading to learn comprehension is critical. In fourth grade, they encounter more abstract concepts that do not necessarily match up with their everyday experiences. Additionally, fourth-grade teachers expect children to be more independent in the learning process, to assume more responsibility for their learning, and to show greater initiative. Perhaps teachers foster this independence by stepping back somewhat and shifting their instructional approach to be less didactic. It is at this point that motivation and self-initiated learning become crucial for childrens later school success. This is the point at which Elkind (1986) and Zigler (1987) worried that short-term academic gains produced by overly didactic, formal instructional practices for young children would be offset by long-term stifling of childrens motivation. Important lessons about independence and self-initiative are being learned in the early childhood years. Overly teacher-directed approaches that tell young children what to do, when to do it, and how to do it most likely curtail development of initiative during the preschool years. According to developmentalist Constance Kamii (1975, 1984), such an approach produces passive students who wait to be told what to think next. Therefore, it is not really surprising that children whose preschool experience may have curtailed initiative would find the transition to the later elementary school grades more difficult. The foundation of critical thinking may be found in early childhood experiences that foster curiosity, initiative, independence, and effective choice. As predicted, earlier sex differences in school achievement favoring girls persisted both at the end of the primary grades and following the transition to the later elementary school years. Going into the transition, the smallest gap between boys and girls academic performance was seen among children who had attended preschool classes where teachers used a quotcombinationquot approach. On the other side of the transition, the smallest gap between the sexes was seen in children who had child-initiated preschool experiences. When academic demands increased, boys whose earliest school experiences involved active, self-initiated learning appeared to be better able to meet these new demands. Although sex differences did not, as predicted, moderate the effect of preschool model across time, the closing of the academic gap between boys and girls following the primary grades was interesting. African American boys do not typically follow the academic pattern of boys in general by surpassing girls following the elementary school years. Might the boys in this predominantly African American sample whose preschool experience was active and child initiated break the pattern and pull ahead of girls, or at least stay close to girls, at the next major educational transition Miller and Bizzells findings (1984) suggest that this outcome is a distinct possibility. And, if so, what is the underlying mechanism by which to account for such a possibility How do cultural factors interact with and moderate the influence of various preschool models The passivity required of children in an overly academically directed approach may be especially difficult for young African American boys. In the preschool years, girls earlier maturation may have allowed them to better process the verbal instruction typical of didactic, academically directed instruction, whereas boys generally slower rate of neurological development may have required a more active, quothands onquot approach found in nondidactic, child-initiated early learning experiences. Lessons learned in the preschool years assuredly carry over into childrens later school careers. The next academic transition, when children leave elementary school, will be especially interesting for understanding sex differences in academic performance of these low-income children. Caution is warranted when interpreting this studys findings. First, and foremost, it is important to remember that the quasi-experimental design used in this research does not establish causality. Although parents did not choose their childs teacher or preschool model, neither did the researcher randomly assign children to preschool model at the beginning of this longitudinal study. This was a field study reflecting typical educational practices where children attend their neighborhood school. Second, because the research design is correlational, other intervening variables between preschool and fourth grade most likely contribute to these findings. For example, schools attended, as well as teachers and classmates, undoubtedly affect childrens later school achievement. Additionally, the influence of family characteristics shown to positively affect educational outcomes of African American children (Luster amp McAdoo, 1996) were not adequately examined in this study of intact groups. Only effects of family income and number of parents were investigated. Future research would be strengthened by greater attention to other family characteristics, such as parental beliefs, that are known to influence childrens development (Sigel, 1985). Third, the follow-up sample did differ somewhat from the original in that it consisted of more minority children who were poorer and more likely to live in single-parent families than the sample originally studied. This difference, along with high attrition, was expected in a city where middle-class children often leave the public school system after kindergarten and children from highly mobile, lower-income families often relocate to a neighboring state. Because policy makers were interested in action research that could benefit children enrolled in their own school district, children who left this school system were not followed. Data from those who left the public schools would be interesting to examine. However, it is unlikely that these new data would have altered findings regarding the influence of preschool model because approximately equal numbers of children from each model were lost. Finally, use of individual children as the statistical unit of analysis, rather than school or classroom means, could limit generalizability of findings due to potential interdependence of grades for children in the same classroom. Unfortunately, even nested analysis of potentially nonindependent observations does not guarantee that statistical assumptions of independence of error will be met (Hopkins, 1982). The large number of schools (and hence of teachers) in this follow-up study reduces the possible effect of any particular teachers grading practices on these findings. Concern about interdependence of grades assigned to children in the same classroom is also somewhat reduced by the competency-based grading system used in this school district. It is important to remember that the large number of schools and teachers sampled in this study enhances, but does not guarantee, generalizability of this studys findings. Childrens later school success appears to be enhanced by more active, child-initiated learning experiences. Their long-term progress may be slowed by overly academic preschool experiences that introduce formalized learning experiences too early for most childrens developmental status. Pushing children too soon may actually backfire when children move into the later elementary school grades and are required to think more independently and take on greater responsibility for their own learning process. References Becker, Wesley C. amp Gersten, Russell. (1982). A follow-up of follow through: The later effects of the direct instruction model on children in fifth and sixth grades. American Educational Research Journal, 19 (1), 75-92. EJ 271 993 . Burts, Diane C. Hart, Craig, H. Charlesworth, Rosalind amp DeWolf, Michele. (1993). Developmental appropriateness of kindergarten programs and academic outcomes in first grade. Journal of Research in Childhood Education, 8 (1), 23-31. EJ 493 673 . Charlesworth, Rosalind Hart, Craig H. Burts, Diane C. Mosley, Jean amp Fleege, Pamela O. (1993). Measuring the developmental appropriateness of kindergarten teachers beliefs and practices. Early Childhood Research Quarterly, 8 (3), 255-276. EJ 474 784. DeVries, Rheta Reese-Learned, Halcyon amp Morgan, Pamela. (1991). Sociomoral development in direct-instruction, eclectic, and constructivist kindergartens: A study of childrens enacted interpersonal understanding. Early Childhood Research Quarterly, 6 (4), 473-517. EJ 441 873 . Elkind, David. (1986). Formal education and early childhood education: An essential difference. Phi Delta Kappan, 67 (9), 631-636. EJ 337 505 . Goffin, Stacie G. (1994). Curriculum models and early childhood education: Appraising the relationship. New York: Merrill. Hart, Craig H. Charlesworth, Rosalind Burts, Diane C. amp DeWolf, Michele. (1993, March). The relationship of attendance in developmentally appropriate or inappropriate kindergarten classrooms to first and second grade behavior. Poster session presented at the biennial meeting of the Society for Research in Child Development, New Orleans, LA. Hopkins, Kenneth D. (1982). The unit of analysis: Group means versus individual observations. American Educational Research Journal, 19 (1), 5-18. EJ 271 990 . Hyson, Marion C. Hirsch-Pasek, Kathy amp Rescorla, Leslie. (1990). The classroom practices inventory: An observational instrument based on NAEYCs guidelines for developmentally appropriate practices for 4- and 5-year-old children. Early Childhood Research Quarterly, 5 (4), 475-494. EJ 423 540 . Kagan, Dona M. amp Smith, Kenneth. (1988). Beliefs and behaviours of kindergarten teachers. Educational Research, 30 (1), 26-35. Kamii, Constance. (1975). One intelligence indivisible. Young Children, 30 (4), 228-238. EJ 121 221 . Kamii, Constance. (1984). Autonomy: The aim of education envisioned by Piaget. Phi Delta Kappan, 65 (6), 410-415. EJ 293 135 . Kessler, Shirley A. (1991). Alternative perspectives on early childhood education. Early Childhood Research Quarterly, 6 (2), 183-197. EJ 431 699 . Lazar, Irving Darlington, Richard Murray, Harry Royce, Jacqueline amp Snipper, Ann. (1982). Lasting effects of early education: A report from the Consortium for Longitudinal Studies. Monographs of the Society for Research in Child Development, 47 (2-3, Serial No. 195). EJ 266 057 . Luster, Tom, amp McAdoo, Harriette. (1996). Family and child influences on educational attainment: A secondary analysis of the HighScope Perry Preschool data. Developmental Psychology, 32 (1), 26-39. EJ 524 920. Marcon, Rebecca. (1990). Early learning and early identification: Final report of the three year longitudinal study. Washington, DC: District of Columbia Public Schools. ED 331 934 . Marcon, Rebecca. (1992). Differential effects of three preschool models on inner-city 4-year-olds. Early Childhood Research Quarterly, 7 (4), 517-530. EJ 458 104 . Marcon, Rebecca. (1993). Socioemotional versus academic emphasis: Impact on kindergartners development and achievement. Early Child Development and Care, 96, 81-91. EJ 478 144 . Marcon, Rebecca. (1999). Differential impact of preschool models on development and early learning of inner-city children: A three cohort study. Developmental Psychology, 35 (2), 358-375. EJ 582 451 . Mayfield, Margie I. (1983). Orientation to school and transitions of children between primary grades. Alberta Journal of Educational Research, 29 (4), 272-284. EJ 292 101 . McClure, Larry, amp Leigh, J. (1981). A sampler of competency-based education at its best. In Ruth S. Nickse amp Larry McClure (Eds.), Competency-based education: Beyond minimum competency testing (pp. 89-94). New York: Teachers College Press. ED 206 675 . Miller, Louise B. amp Bizzell, Rondeall P. (1984). Long-term effects of four preschool programs: Ninth - and tenth-grade results. Child Development, 55 (4), 1570-1587. EJ 305 776 . Miller, Louise B. amp Dyer, Jean L. (1975). Four preschool programs: Their dimensions and effects. Monographs of the Society for Research in Child Development, 40 (5-6, Serial No. 162). EJ 138 519 . Mills, Paulette E. Dale, Philip S. Cole, Kevin N. amp Jenkins, Joseph R. (1995). Follow-up of children from academic and cognitive preschool curricula at age 9. Exceptional Children, 61 (4), 378-393. EJ 497 634 . Pfannenstiel, Judy, amp Schattgen, Sharon F. (1997, March). Evaluating the effects of pedagogy informed by constructivism: A comparison of student achievement across constructivist and traditional classrooms. Paper presented at the annual meeting of the American Educational Research Association, Chicago. Pollard, Diane S. (1993). Gender, achievement, and African-American students perceptions of their school experience. Educational Psychologist, 28 (4), 341-356. Rawl, Ruth K. amp OTuel, Frances S. (1982). A comparison of three prereading approaches for kindergarten students. Reading Improvement, 19 (3), 205-211. EJ 269 746 . Reynolds, Arthur J. (1989). A structural model of first-grade outcomes for an urban, low socioeconomic status, minority population. Journal of Educational Psychology, 81 (4), 594-603. EJ 404 602 . Richardson, Stephen A. Koller, Helene amp Katz, Mindy. (1986). Factors leading to differences in the school performance of boys and girls. Journal of Developmental and Behavioral Pediatrics, 7 (1), 49-55. Rowan, Joseph L. (1989). The effect of gender on non-promotion of Black males. Unpublished manuscript. ED 313 456 . Schweinhart, Lawrence J. amp Weikart, David P. (1997). The HighScope preschool curriculum comparison study through age 23. Early Childhood Research Quarterly, 12 (2), 117-143. EJ 554 350 . Schweinhart, Lawrence J. Weikart, David P. amp Larner, Mary B. (1986). Consequences of three preschool curriculum models through age 15. Early Childhood Research Quarterly, 1 (1), 15-45. EJ 334 891 . Shepard, Lorrie A. amp Smith, Mary Lee. (1988). Escalating academic demand in kindergarten: Counterproductive policies. Elementary School Journal, 89 (2), 135-145. EJ 382 617 . Sigel, Irving E. (1985). Parental belief systems: The psychological consequences for children. Hillsdale, NJ: Erlbaum. Stipek, Deborah Feiler, Rachelle Daniels, Denise amp Milburn, Sharon. (1995). Effects of different instructional approaches on young childrens achievement and motivation. Child Development, 66 (1), 209-223. EJ 501 879 . Vartuli, Sue. (1999). How early childhood teacher beliefs vary across grade level. Early Childhood Research Quarterly, 14 (4), 489-514. EJ 631 458 . Walsh, Daniel J. (1989). Changes in kindergarten: Why here Why now Early Childhood Research Quarterly, 4 (3), 377-391. EJ 402 845 . Weikart, David P. Epstein, Ann S. Schweinhart, Lawrence J. amp Bond, James T. (1978). The Ypsilanti preschool curriculum demonstration project: Preschool years and longitudinal results (Monographs of the HighScope Educational Research Foundation, 4). Ypsilanti, MI: HighScope Press. ED 156 756 . Zigler, Edward. (1987). Formal schooling for four-year-olds No. American Psychologist, 42 (3), 254-260. EJ 355 124. Author Information Rebecca A. Marcon, Ph. D. is a developmental psychologist and a professor of psychology at the University of North Florida. She received her B. A. in psychology from California State University-Fullerton and her M. A. from the University of California, Los Angeles. After working as a school psychologist in the barrios of east Los Angeles, she left California to pursue her Ph. D. in developmental psychology at Louisiana State University. Since completing her Ph. D. she has been a faculty member in the Departments of Psychology at Clemson University, Davidson College, and the University of North Florida. She was also a senior research associate in the District of Columbia Public Schools where she initiated an ongoing longitudinal study of early childhood educational practices. Her research interests include social and language development, early intervention, and public policy. She continues to serve young children and families in the District of Columbia Public Schools as a researcher and consultant. Dr. Marcon also is actively involved with Head Start programs serving young children in northeast Florida. She is a member of the Early Childhood Research Quarterly Editorial Board and serves as a Research in Review Editor for Young Children. Rebecca A. Marcon, Ph. D. Department of Psychology University of North Florida 4567 St. Johns Bluff Road, South Jacksonville, FL 32224-2673 Office Bldg. 39-4072 Telephone: 904-620-2807 Fax: 904-620-3814 Email: rmarconunf. edu This article has been accessed 71,587 times through June 1, 2007.Moving to Puerto Rico Whether it is for school, work or for any other reason, moving to Puerto Rico requires a lot of coordination. Before purchasing a one-way ticket to the island, there is a lot that you need to know before you arrive. Here are some basics to get you started. Shipping a Car When considering transporting automobiles, furniture and other large household items over land and sea, remember that it may be more economical to sell certain items than it is to ship them -- for instance, older cars valued at less than a thousand dollars. Shipping a car or household items usually takes from 7 to 14 days, assuming that the request was received at least a 1 to 2 week in advance. Check with your local marines cargo company or an authorized trucking company for schedules and prices. In addition, contact the Office of Excise Taxes at (787) 721-6237 or (787) 721-0338 in Puerto Rico to obtain an approximate amount for the excise tax you will need to pay to bring your vehicle to the island. You will need to provide vehicle information: make, model, year, automaticstandard, and number of doors. License plates are not transferable. License stickers are renewed every year at which time you will have to pay 35 annual fee for no fault insurance and 65 for annual registration. For more information contact the Departamento de Transportacioacuten y Obras Publicas (dtop. gov. pr) at (800) 981-3021 or (787) 729-2929. Cost of Living The cost of living in Puerto Rico index averaged 79.11, way below the national average of 100 (ACCRA Cost of Living Index, 2013). Housing prices in Puerto Rico are comparable to Miami or Los Angeles, but property taxes are considerably lower than most places in the US. The real estate market in Puerto Rico is booming due to population growth. Real Estate agencies are a good starting point for renting or purchasing property. Newspapers ads and the Internet is another possible way to find housing. There are thousands of property ads appearing every day in newspapers, web sites and magazines. Puerto Rico Home Prices and Home Values (US States and Locations Near Puerto Rico Comparison) Median List Price () Puerto Rico Virgin Islands Florida South Carolina North Carolina Georgia California New York Texas Source: Zillow Local Info, January 29, 2013 Titles, Deeds and Land Records Land records are available through the Registros de la Propiedad. There are 29 offices that serve specific municipalities, neighborhoods or sectors. To obtain information from these records it is usually necessary to know the name of the purchaser, the approximate date of purchase and the city in which the land was then located. To obtain certified copies write to or call: Registro de la Propiedad Oficina de la Directora Administrativa Departamento de Justicia, Piso 3 Calle Olimpo, Esq. Axtmayer Pda. 11 Miramar, San Juan, PR 00907 P. O. Box 9020192 San Juan, Puerto Rico 00902-0192 (787) 723-8960 (787)723-7560 Fax (787)725-8925 Finding Work in Puerto Rico If you do not have a job, before you have arrived, make sure you have done your resume (curriculum vitae) and that you have copies of all relevant documentation, such as up to date references. For applicants of 18 years or more some employers may require a Certificate of Good BehaviorCertificate of No Criminal Conviction (PDF), which is issued by the Puerto Rico Police Department. There are different methods to find a job in Puerto Rico. Here are a few tips: Ask for job leads from: family members, friends, people in the community, and staff at career centers. Knock on the doors of any employers, factories, or offices that interest you, whether or not they have vacancies. Use the Yellow Pages to identify areas that interest you in or near the town or city where you live and then call the employers in that field to find out whether they are hiring for the position that you can do -- and do well. You can also find lots of job offers in newspapers, specialist magazines and on the Internet. Although you may find a job through one of the many Internet job search sites, the best use of the Internet is to research companies you may want to work for. If youre looking for employment in Puerto Rico, these web sites can help you in your job search. How to obtain a Certificate of Good BehaviorCertificate of No Criminal Conviction You may request a certificate by completing the Certificate of No Criminal Conviction application (PDF). You must also include a postal money order in the amount of 1.50 made out to: Secretario de Hacienda. Send the money order and letter to: Superintendente Auxiliar Servicios al Ciudadano Policia de Puerto Rico P. O. Box 70166 San Juan, PR 00936-8166 For more information call (787) 781-0227. Puerto Ricos overall literacy rate of 90 percent and its budget for education is approximately 40 percent. Education is obligatory between 6 to 17 years old. Primary school consists of six grades the secondary levels is divided into 2 cycles of 3 years each. The school term in public schools starts in August through mid-December and January through late May. The Department of Education oversees the public education system. The language used in the schools is Spanish, however, English is taught from kindergarten to high school as part of the school curriculum. Some private schools provides English programs where all classes are conducted in English except for the Spanish class. There are also several colleges and universities available throughout the island, including: University of Puerto Rico, Interamerican University of Puerto Rico, among others. Utilities, Newspapers Communications Electricity The general rule in Puerto Rico is United Standards 110 and 120 volts AC, and the outlets take the same two-prong plugs found in the United States. Electrical service is provided by the Puerto Rico Electrical Power Authority (PREPA) (Autoridad de Energiacutea Eleacutectrica) (aeepr), the second largest government owned utility in the U. S. with assets of 3.5 billion in 1995. It is also the only supplier of electricity in Puerto Rico. Electricity bills are to be paid every month. For more information contact the Customer Services Center at: (787) 289-3434, outside the metro area 1-800-981-2434 or visit the nearest office. New generators are being built to keep up with the demand by adding almost 1,500 megawatts of capacity by 2001. Expansion is part of a five year, 1.6 billion capital improvement program. Two private co-generating plants are under construction. The first, a 600 million facility, broke ground in March of 1998. - Electric voltage 110V, 60-CYCLES, AC - Capacity 5,040,000 kW. - Production 20.02 billion kWh (2011 est.) - Consumption 19.43 billion kWh (2010 est.) Water amp Sewage The island is served by Puerto Rico Aqueduct and Sewer Authoritys (PRASA) (acueductospr) (Autoridad de Acueductos y Alcantarillados) extensive system of over 10,000 miles of water mains and aqueducts and 2,000 miles of sewage lines. Puerto Ricos water quality is subject to the same regulated EPA standards that apply on the U. S. mainland. A private company, Professional Services Group, manages and operates PRASAs system. Tap water is considered safe to drink. Milk is pasteurized and dairy products are safe for consumption. Local meat, poultry, seafood, fruit and vegetables are generally considered safe to eat. For more information contact Autoridad de Acueductos y Alcantarillados Customer Service at: (787) 620-2482. Natural Gas Natural gas is delivered by the cylinder. Many Puerto Ricans use natural gas propane stoves instead of electric stoves. Propane cylinders can be obtained from a local propane gas supplier. Solid Waste Puerto Rico has over 32 landfills and waste-burning facilities. As with electricity and water, the only supplier of garbage disposal is the government-run company called Autoridad de Desperdicios Solidos (ads. gobierno. pr), known as ADS. For more information call the main office at: (787) 765-7575 or or contact the nearest office (PDF). Communications U. S. by high capacity submarine cable and INTELSAT with high-speed data capability digital telephone system with about 1 million lines cellular telephone service broadcast stations - 50 AM, 63 FM, 9 TV cable television carries all four major U. S. networks. The first local radio broadcast dating from 1923 and television from 1954. Dow Jones and Reuters are among the quotation and news services available. Daily Newspapers (national): 4: El Nuevo Diacutea (endi) (The new day), El Vocero de Puerto Rico (The voice of Puerto Rico), The San Juan Star (thesanjuanstar), and Primera Hora (First hour). Daily Newspaper Circulation: 650,000 (1998) Daily Circulation: 185 per 1000 persons Newspapers Advertising Revenues: 250 million Total Radios: 2.7 million (1997) Radios: 679 per 1000 persons Radio broadcast stations: AM 74, FM 53, shortwave 0 (2006) Television broadcast stations: 34 (2008) Total televisions: 900,000 or 99 of total households Televisions: 1.021 million (1997) Television broadcast stations: 18 (plus three stations of the US Armed Forces Radio and Television Service) (1997) TV Stations: Telemundo (WKAQ), Televicentro (WAPA), and TELE ONCE . Television Revenues: 1.5 million (1998) Cable TV subscribers: 280,000 (1998) Puerto Rico has modern, reliable United States style telephone service (area calling codes are 787 and 939). All local calls costs 25 cents. Local information is 411, 1-787-555-1212. For directory assistance to others parts of Puerto Rico, dial 0. Person-to-person, collect and calling card calls are easy to place. At the center of the phone book are blue pages in English. Total Telephones (main lines in use): total subscriptions: 813,106 subscriptions per 100 inhabitants: 23 (July 2015 est.) Total Telephones (mobile cellular): total: 3.205 million subscriptions per 100 inhabitants: 89 (July 2015 est.) Telephone Service Providers: Companies providing local and long distance services include: ATT. Sprint, and MCI among others. Internet service companies provide access to the Net through local telephone calls around the island. National providers includes: ATampT, America On-Line, CompuServe, MSN and Sprynet. Local providers: Datacom Caribe, Inc.. Caribbean Internet Services (now a PSINet Company), and PRTC. Internet country code. pr Internet hosts: 469 (2012) Internet users: total: 2.86 million percent of population: 79.5 (July 2015 est.) Companies providing mobile-phone, paging and celluar services include: Centennial de Puerto Rico (centennialpr ), Verizon Wireless (verizonwirelesspr), among others. Companies providing Cable TV services include: Adelphia (adelphiapr), Centennial de Puerto Rico (centennialprcabletv), Liberty Cablevision (libertycablevision), among others. Postal Service Puerto Rico is part of the U. S. postal system (USPS ) and has the same mail rates (28cent for a postcard, 44cent for a first-class letter) and service as provided on the U. S. mainland. Post offices are located in every city and offer Express Mail next-day service to the U. S. mainland and Puerto Rico. In addition, express services are offered by FedEx, UPS, Emery, RPS, and DHL. Taxes in Puerto Rico Puerto Rico has a 6.0 sales tax. Municipalities have the option of imposing an additional sales tax of up to 1.0 (effective on November 15, 2006). In addition, in the event that the governor determines an insufficiency in collections for the general fund an additional 1 to the central government will be imposed. Puerto Ricos combined sales and use tax rate is currently 7. All inbound shipments to Puerto Rico are subject to a local excise tax. Merchandise andor articles arriving from the U. S. that will be sold, consumed, given away, andor remain in Puerto Rico are subject to a 6.6 Puerto Rico excise tax that is calculated from the commercial invoice value. This is payable upon entry to Puerto Rico. Puerto Rico has it own tax system. Although it is modeled after the U. S. system, there are differences in law and tax rates. The Puerto Rico tax system is based on self-assessment. Taxes are paid to the state. In addition, a premium is paid to the Social Security. Individual taxpayers are required to file an annual income tax return when minimum-income thresholds are met. They report taxable income and deductions, compare their final tax liability to any income tax withheld or estimated tax paid, and determine any balance due or overpayment of tax due from the Treasury. For information about the filing taxes in Puerto Rico contact the Bureau of Income Tax at the following address: Negociado de Asistencia Contributiva y Legislacioacuten Departmento de Hacienda P. O. Box 565 San Juan, Puerto Rico 00902-6265. The telephone number is (787) 721-2020, extension 3611. To obtain tax forms and instruction booklets contact the Forms and Publications Division Office at the above address, call (787) 721-2020, extensions 2643, 2645, or 2646, or visit their web site (hacienda. gobierno. pr). Health and Medical Facilities Regulations and requirements may be subject to change at short notice, and you are advised to contact your doctor well in advance of your intended date of departure. Good medical facilities exist in Puerto Rico. Every hotel has a doctor on call for guests. Law requires immunizations for diphtheria, tetanus, whooping cough, and rubella. Immunizations are required for school registration. Drivers License and Drivers Records The process of obtaining a Puerto Rico driver license is easy to follow. When you apply for your license, take the following basic information: Social security card, ID with your full name, residential and postal address, date of birth and drivers license number (if applicable). To apply, visit one of the locations listed on the on the DMV website. Learners Permit Certificate A learners license allows you to practice driving while accompanied by a licensed adult age 21 or older. You must be at least 16 to apply. You can study for the written permit test using the Drivers Manual (PDF) provided by the DTOP available online. To apply you must provide the following: Application for Driver License (form DTOP-775) (PDF) If you are under 18 years of age, but older than 16 years of age, parent or legal guardian must present birth certificate (acceptable forms of identification ) (PDF) and complete a notarized Parental affidavit Medical certificate (form DTOP-260) Social Security number (present Social Security card, W-2 form, SSA-1099, US Military card, or copy State or Federal Tax returns) Provide proof of residence and birth date (birth cerificate or passport - acceptable documents ) (PDF) Three 2x2 photographs Internal Revenue Seal of 11.00 Pass the written exam Learners Permit Certificate with at least 30 days of expedition Pass the driving exam Three 2x2 photographs Internal Revenue Seal of 11.00 If you wish to retake the exam you should present an Internal Revenue Seal of 5.00. Renew of Drivers License Complete the Application for Driver License (PDF), including medical certificate Two 2x2 photographs Internal Revenue Seal of 11.00, if your license has expired you must present one for 31.00 If your license has been expired for more than 2 years and 30 days, you must take the written exam applicable for your license type. Drivers License for New Residents New residents must obtain a valid Puerto Rico drivers license within 30 days of establishing residency and may register to vote after 30 days. If you are a U. S. Citizen and you have a valid out-of-state license you must provide the following: Take an eye exam Pass the written exam, (if you are over 25 and your current license has no outstanding violations, the written exam could be waived) Internal Revenue Seal of 11.00 In most instances eye and written exam is not required when presenting a a valid drivers license from another state. Duplicate of Drivers License Affidavit on the loss of the license, indicating that has not been occupied by the Police or suspended by some court of Justice Two 2x2 photographs Internal Revenue Seal of 5.00 Identification with photo How to obtain a drivers record You may request a driver record by mail by providing the following information: Full name as it appears on your drivers license Social Security number License number Reason for the request Address to which the record should be mailed Daytime telephone number Photocopy of a valid photo identification, preferably your Puerto Rico drivers license Money order in the amount of 1.50 made out to: Secretario de Hacienda. Mail to: Secretario de Hacienda DivisiApartado 41243 San Juan, PR 00940-1240 Requests usually take 2 to 3 business days and mailed out via first class US Mail. Vehicle Registration and Insurance Information To register your car you must present vehicles current registration certificate, title (unless held by lien holder), and your out-of-state license plates. Puerto Rico law does not require drivers to carry vehicle insurance. Voter Registration To register to vote applicants must be a U. S. citizen, 18-years-old by the election date and have lived in the state and county for at least 30 days and within their precinct 10 days prior to the election. There is a good representation of all the major religious denominations in most towns: Roman Catholic, Christian Scientist, Presbyterian, Methodist, Evangelists, Islam, Scots Kirk, Seventh Day Adventists, Jehovahs Witnesses, Salvation Army, Church of Christ, Mennonite, etc. Book Your Trip