Read the study description below:
A college researcher wanted to investigate student attitudes toward the college's new internal environmental sustainability initiative. They used an opportunity sample by recruiting students from the science block's common room. Consequently, all of the recruited students turned out to be studying STEM subjects.
Explain how using stratified sampling might improve the design of this study.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.