What are the unintended effects of the researcher's presence on participants' behaviour?

• A. Interview bias
• B. Focus group
• C. Hawthorne or Observer Effect
• D. Laboratory experiments

Answer: (C)

The Hawthorne effect is the idea that people change their behavior simply because they know they are being observed by researchers. When participants are aware of a study or the presence of researchers, they may work harder, act more cooperatively, or alter their responses, not because of the actual manipulation being tested but because they want to fit what they think the researchers expect. This unintended shift in behavior can bias results and make it hard to tell whether observed changes are due to the study variables or to the act of observation itself. It’s not about interview bias, which is about how questions or the interviewer's conduct shape responses; and it isn’t about a focus group or lab experiments as methods themselves—those are different aspects of research design. The key idea here is that presence-induced behavior change, captured by the Hawthorne or observer effect, can distort findings.