As stated in the following website
the JIGSAW CLASSROOM is a cooperative learning technique that promotes better learning, improves student motivation and increases enjoyment of the learning experience. Fifth grade students are studying one of the units on their NATURAL SCIENCE textbook using this technique.
First, I divided the class into six groups. Each group was in charge of a different part of the unit. They read and took notes about that part. Textbook is allowed only at this point of the process.
Second, you mix the groups . Every group is now composed of six members, one from every group. They must explain the other members their part of the unit and the others must take notes.
Third: when all the members have spoken, the return to their original group. They have to put in common all the information the have collected. In this way, they will obtain all the information about the unit.
In the following pictures you can see students, fully engaged, during the second step of this process.