AU - الربيعان، وفاء بنت محمد بن عبد الله. AB - This study is aimed to investigate the effectiveness of flipped classroom in developing critical thinking in science for intermediate schoolgirls in Riyadh. The study used the experiment method (quasi-experimental design). The tools of this study are: a critical thinking test, which was made by al-Sharqee [1], students guide, designed digital videos, and a teacher guide. The sample is consisted of 103 students of third year intermediate schoolgirls, divided into two groups, control group (51) and experimental group (52). The study revealed the following results: There is a statistically significant difference between the mean scores of experimental group and control group in the post application of critical thinking skills-recognition, assumptions, interpretation, inference, deduction. After using flipped classroom in fever of experimental group after application, there is no a statistically significant difference between the mean scores of experimental group and control group in the post application of critical thinking skills (evaluation of arguments). The study found a set of recommendations, the most important is: the training of teachers on flipped classroom to enhance critical thinking skills. (Published Abstract) http://search.shamaa.org/abstract_en.gif ID - 117005 OP - ص ص. 188-201 T1 - فاعلية الصف المقلوب بمنصة إيزي كلاس (EasyClass) لتنمية مهارات التفكير الناقد في مقرر العلوم لدى طالبات المرحلة المتوسطة في مدينة الرياض [مقال] UL - 1 http://search.shamaa.org/fulltext.gif http://www.iijoe.org/v6/IIJOE_13_02_06_2017.pdf النص الكامل (PDF)