EXPERIMENTER EXPECTATIONS

Experimenter Bias/ Experimenter Effect

Any influence a researcher may have on the results of their research, derived from either interaction with participants or unintentional errors of observation, measurement, analysis, or interpretation.

Observer Effect / Hawthorne Effect / Reactivity

A participant changes their behavior simply as a result of being observed.

Experimenter Expectancy Effects

Researcher’s expectations about the findings of their research are inadvertently conveyed to participants and influence their responses. 

Demand Characteristics 

Cues that may influence or bias participants behavior, for example by suggesting the outcome or response that the experimenter expects or desires. 

Clever Hans Effect

Unconscious nonverbal communication of information from a researcher to an animal, for example bunny the talking dog.

Double Blind Trials

A procedure in which both the participants and the experimenters interacting with them are unaware of the particular experimental conditions.