Based on the definitions, the writer concludes that cooperative learning is a method of learning where the students work in a group in order to help each
other making sure that their group members understand toward the given topic. Each member of a group is responsible for learning and helping their teammates
to achieve the objective of the study. In the cooperative learning, teacher as the facilitator, a resource, and observer while the students work in a group to get
knowledge even discuss to solve the problem. There are a lot of techniques that can be used in cooperative learning such as jigsaw, round robin brainstorming,
round table, numbered heads together, think-pair-share, three steps interview, group grid, silent card shuffle, etc.
In this study, the writer chooses one of the cooperative learning that is numbered heads together technique. The writers wants to prove whether the use
of numbered heads together technique will be effective to improve the students‟ mastery and motivation in learning irregular past forms. In this research, the
writer will combine numbered heads together technique with crossword puzzle as the medium of teaching and learning process. The further information about
numbered heads together technique will be explained in the next sub-subchapter.
2.2.6.2 The Characteristic of Cooperative Learning
Cooperative learning has its own characteristic like the other methods. According to Larsen-Freeman 2000:167-168, there are nine principles of
cooperatives learning which is mentioned as follows: 1
Students are encouraged to think cooperatively and have positive interdependence.
2 Students stay together in the same groups for a period of time, so they can
learn how to work together and learn from each other in a group. 3
The individual‟s effort can help others in the class. 4
Social skills, such as students‟ contribution, need to be explicitly taught. 5
Language acquisition is facilitated by students interacting in the target language in a group.
6 Each student is individually responsible in working together in a group.
7 Responsibility and accountability for each other‟s learning are shared.
8 Each group member should be encouraged to feel responsible in
participating and learning in a group. 9
Teachers not only teach language, but also teach a good cooperation.
Besides, the characteristics of cooperative learning based on Kagan 2009:5.10 are:
1 Positive Interdependence
Each student in a group has contribution to make one another to achieve the goal. The success of one student is linked to the success of the other
students in a same group. The students help each other in supporting each other‟s learning.
2 Individual Accountability
All students in a group must be responsible for contributing their ideas and thought toward the given material.
3 Equal Participation
In a group of cooperative learning method, each student must have equal participation in achieving the group‟s success. A student is not permitted to
dominate the group‟s works, because each student must have same portion of participation.
4 Simultaneous Interaction
In cooperative learning, the students not only participate in the group‟s work equally, but also frequently.
2.2.6.3 The Advantage of Cooperative Learning
