Three major types of questions are causal/comparative, relationship, and impact. Use a literature review as a funnel to narrow a broad area of research into a manageable contribution, which leads to "The purpose of this study is..." Classic or landmark studies would be considered good content for the introductory, broad part of the literature review. Use incremental blocks of studies as a transition to more focused topics in your area of research. The final question should be something you are genuinely interested in finding the answer to so you have the motivation to complete the report as time progresses.

The question should have a question mark at the end. The question should ask if there is a cause/effect, what impacts what, or if there a relationship (what two or more things are related). Should have a construct or construct level at the start that is narrowed down to something very specific. Could "self concept" really mean "body image"? Does "achievement" mean achievement in math, reading, overall, or something else? Include operational definitions for parts of the question to define "achievement" if you are looking for relationship between achievement and yearly income. Perhaps achievement has several six factors to consider observing in the study.