Since the classes existed as intact groups, the study
used a quasi-experimental non-equivalent control group
design. To control for teachers’ training and experience
as sources of internal invalidity, only teachers of
equivalent training and experience were chosen.
Convenience sampling technique was used to select the
schools that formed the study sample. The participants
were 82 Form One students from one of the school in
Miri, Sarawak. Of these respondents, 44 were in the
experimental class, while 38 others were in the control
class. Students in Form One in Malaysian secondary
schools are of an average of 13 years old. The study
was carried out for two weeks. Student Teams-
Achievement Divisions (STAD) developed by Slavin
(1995) was used as the cooperative model.