Final answer:
The term describing when subjects behave differently due to being observed is known as the Hawthorne effect. This effect can introduce bias into a study, and researchers often use strategies like blinding and control groups to minimize such biases.
Step-by-step explanation:
The term often used to describe any aspects of a study that communicated to the participants how the experimenter wants them to behave is experimenter bias.
However, in the context provided, when study subjects behave differently because they are aware of being observed, the term that specifically refers to this phenomenon is the Hawthorne effect.
The Hawthorne effect occurs when people change their behavior in response to their awareness of being observed.
This awareness can introduce artificiality into research because subjects might try to conform to what they think the researcher expects of them.
A well-designed experiment will attempt to minimize experimenter bias and control for effects like the Hawthorne effect by employing strategies such as blinding and proper control groups.