Consider this invented business dissertation idea: “Does social media change student shopping?” It leaves several choices unresolved. Which social media content, which students and what kind of shopping? “Change” also suggests a causal claim that a simple account of people’s experiences cannot establish.
A more focused exploratory question is: “How do final-year business students at one university describe the role of short-video product reviews in a recent clothing purchase?” This identifies a group, a type of content and a decision. It asks about reported experience, rather than claiming to measure an effect across all students.
Interviews could explore how those students describe the purchase: what they noticed, how they judged the review and what else influenced their decision. The trade-off matters. Their accounts would not, by themselves, show that the videos caused purchases or tell you how common the pattern is across UK universities. You would still need a feasible recruitment plan, a way to analyse the material and your university’s required approvals before collecting data.
If the real aim were to measure a numerical association between review-viewing and purchasing, the question and design would need suitable measures, sampling and statistical reasoning. Choosing a questionnaire simply because it feels quicker would not resolve those decisions.
For independent practice, write two questions about a different invented topic, such as students choosing a place to study: one about their experiences and one about frequency or numerical association. For each, explain what evidence you would need, why a proposed method fits and one conclusion it could not justify. This tests the reasoning without supplying an answer for an assessed dissertation. Your course’s rules still determine whether paid help with that practice is permitted.