This development project aims to apply cooperative learning in 4th grade to increase the concept(conceptual) understanding, in the knowledge area of water, in comparison to traditional teaching. Further, the project aims to share how students in 4th grade experience cooperative learning in science subjects.

To achieve the aim, these following two questions have been formulated:

1. How does cooperative learning affect students' conceptual understanding in comparison with traditional teaching?

2. How do students in 4^th grade experience cooperative learning in science subjects?

A total number of 87 students participated in the project. To be able to compare the effects of cooperative learning on concept understanding, 44 students participated as an experimental group in cooperative learning and 43 students as a control group in traditional teaching. Exams, surveys, and interviews were used as methods to achieve the aim of the study. The result shows that cooperative learning does increase student's concept understanding more than those students who had traditional teaching.

The results of this study show that cooperative learning affects students' conceptual understanding positively. The experimental group taught in cooperative learning performed better and had a better conceptual understanding than a control group who was taught in traditional teaching. The result also shows that the students have positive experience towards cooperative learning and that majority of the student would like to work in groups next time working with conceptual understanding in science subjects.