identify the Effect of Teaching Science with the use of Needham’s Constructivist Model on Development Depth of Scientific Knowledge Levels and Higher Order Thinking Skills and their relationship among second grade

   The Research aimed at identify the  Effect of Teaching Science with the use of  Needham’s Constructivist Model on Development Depth of Scientific Knowledge Levels and Higher Order Thinking Skills and their relationship among second grade
of prep stage pupils. To achieve these objectives The Depth of Scientific Knowledge Test and Higher Order Thinking Skills Test were prepared, The Research group consisted of(74) students,(37) e students of the Experimental group and (37) of the control group, from second grade of prep stage pupils in Safaga Preparatory School for Girls ,A hand book has been prepared for  students  on  2019/2020, according to Needham’s Constructivist Model .in addition , A instructor manual has been to guide in teaching the unit of the subject of the  study has been prepared ,Pre-‌post  testing was administreted  and statistically and apply after that on students ( research group) and data were analyzed. The results Research pointed to the following : the use of Needham’s Constructivist Model in Teaching Science  was Big  Effect  in the Development of Depth of Scientific Knowledge Levels and Higher Order Thinking Skills to  second grade of prep stage pupils. Results also showed the presence of a statistically significant positive relationship at (>0.01) level of significance between the depths of scientific knowledge levels and Higher Order Thinking Skills to  second grade of prep stage pupils