Method
Research Design
The study employs a quasi-experimental research design. The subjects of the study
were two groups of 6th grade pupils of a state/public primary school in Izmir, Turkey. The
number of pupils in both experiment and control groups were the same i.e. each group was
consisted of 35 pupils. The school did not allow the researchers to assign control and
experimental groups randomly. However, both groups of pupils were similar in terms of
number of pupils, gender compositions, academic achievement level in the school and their
socio-economic status before the experiment. Those variables were treated as covariates in
the analysis.