What is bias in psychological research and give an example?

• A. Bias is a random error that occurs by chance.
• B. Bias is a systematic error that affects results; example: experimenter expectancy effect where researchers influence participants' responses.
• C. Bias is the tendency for researchers to ignore data that contradict their hypothesis.
• D. Bias is a flaw that only occurs in qualitative studies.

Answer: (B)

Bias in psychological research is a systematic error that skews results in a particular direction, not just random fluctuation. It means the way a study is designed, conducted, or interpreted introduces a consistent distortion. A classic example is the experimenter expectancy effect: researchers’ own expectations subtly influence participants’ behavior or how responses are recorded, so the data reflect the researchers’ beliefs rather than the actual phenomenon. To prevent this, researchers use strategies like double-blind procedures, standardized instructions, random assignment, and objective measures. Remember, bias is not random error, and it can occur in any type of study, including quantitative ones.