CHANGES IN THE TEACHER-STUDENTS ROLES BY COOPERATIVE LEARNING STRATEGIES
In the last years, cooperative learning has become one of the most researched of all the new teaching strategies. Cooperative and collaborative learning differ from traditional teaching approaches because students work together rather than compete with each other individually . Group composition and the process of group formation may have complex effects on the success of collaborative learning. The students of different levels of ability are distributed in small teams. Assigning roles to students is one way to encourage positive interdependence, interaction, and group processing, which are among the five key elements of working in groups .
Cooperative and collaborative learning models generate changes in both teacher and students roles. It is necessary an adequate plan in which the students know which is their role into the team and the activities must be designed to promote cooperation and mutual assistance among learners and often carry over to relationships outside the University. The teacher acts as a guide, offering detailed instructions to students on how to work in a collaborative way to learn. The students must use a variety of tools to improve their understanding of a topic proposed by the teacher. Each member of a group is responsible not only for learning what is taught but also for helping teammates learn, thus creating an atmosphere of achievement. Students work through the assignment until all group members successfully understand and complete it.
The main techniques used in our experience were puzzle and technical research group. At the beginning of the theme the teacher explains the basic concept and makes the distribution of the different subjects among the groups. Each group should explain the basic and highlight concepts in an oral presentation. Finally, the teacher asked different problems in which the students have to develop the protocol to follow in order to obtain an adequate answer. On this way, the student participates actively in the development of the theme. All students would make questions and the group is graded. With all students and teacher marked the group obtained the final mark.
Several interviews made to students indicate the positive attitude toward using of collaborative learning activities and students expressed agree that through cooperative learning achieved greater development of general skills.
 A. Fernández López, M. J. Rodríguez Fórtiz, M. Bermúdez Edo, and M. Noguera García. Improving the cooperative learning of people with special needs: A Sc@ut platform extension. Research, Reflections and Innovations in Integrating ICT in Education. (2009), Vol. 2: 1161- 1166.
 D. W. Johnson, and R.T. Johnson and M.B. Stanne. Cooperative learning methods: a meta-analysis. (2000), http://www.clcrc.com/pages/cl-methods.html.