Developing the traditional instruction based on Jig-Saw cooperative model of teaching.

Models of teaching is important tool in paving the way for organizing education oriented toward benefiting from variety of intelligence and improved learning. Cooperative models in its suitable approach to problem solving, thinking and research brings up facilities with regard to program and goals. Cooperative models are submits of social family models of teaching and aims at teaching cooperation. In that, students have vital role. Teacher is a guide and leader and is responsible for condition of learning. In designing new plan for Iran educational system the participative models of teaching has an important role to play. There is variety of cooperative learning models and Jigsaw is the important ones. In that, the student cooperates in complete goal achievement and the implementation of the assigned task. It is usual to made students study a chapter of a book in teams. Then, each member studies a section of that chapter, and is responsible in teaching it to the other team members. Jigsaw class, rather than making feeling security and intimacy, prevents climate with absent of cheating, aggressive competitions and negative affection and jealousy. It helps transference of Knowledge and science and expansion of skills with aimed and suitable model to students.In the present semi-experimental research the independent variable is Jigsaw and the dependent one is students achievement. 111 students in three 5th grade class made experimental group and 99 students in whole fifth grade and six elementary classes in the district 2 Robat Karime. Students in control group learns history subject in a traditional way (teacher center using lecture). The effect size was 1.08 which means that the experimental mean was at the 80th percentile of the normal curve distribution of the whole class. The result is the significant difference in students achievement. The above mention results only shows the counted direct effect of Jigsaw whereas, its indirect or nurturing effects such as, social, individual, cognitive, behavioral skills and self awareness of students, which are also significant, have not been counted. The result of this research predicts its implication for the other subjects. The use of effect size formula for counting the effect of any new model of teaching is recommended.