What is the Hawthorne effect?

• A. The Hawthorne effect is a measurement error due to instrument drift.
• B. Changes in behavior resulting from participants' awareness of being observed.
• C. A type of bias that occurs when participants drop out.
• D. An effect observed only in longitudinal studies.

Answer: (B)

The Hawthorne effect is the phenomenon where individuals change their behavior simply because they know they are being observed or studied. Originating from early research at the Hawthorne Works, productivity appeared to rise when researchers were present, even when the work conditions didn’t change. The important idea for experiments is that participants may act in ways they think the researchers expect, or otherwise modify their behavior due to the attention, rather than due to the actual experimental manipulation. This can confound results, since observed changes may reflect the presence of observation rather than the thing being tested. It differs from measurement errors in instruments, which misread data, from dropout bias, which comes from participants leaving the study, and it isn’t limited to longitudinal designs—being watched can influence behavior in various study types.