You could split your respondents into two groups: 1) For the first group, ask the questions you need to in order to find out their interest in environmental science, and 2) for the second group, ask questions related to some other academic concern (for example, interest in the community, or in exercising to be healthy, etc.). This might help you determine if one grade level is just less willing to answer survey questions, etc.
Hi Tugba,
I would caution against a control group approach in education, particularly in relation to primary school students, as it is very difficult to control for the variables - teacher, students, day of the week when lessons are delivered, use of technology, pedagogical style etc.
Maybe you could do a very basic control experiment, as suggested by Kelsey - but you will almost certainly need to also do some qualitative investigation as well.
Regards, Kevin
I think this study isn't experimental study. This study is comparative study. Thus there isn't experimental and control gorups. For this study collected data analyses with ANOVA. Dependent variable is amount of interesten in environmental science. Independent variable is grade levels.