Reactivity is a phenomenon that occurs when individuals alter their performance or behavior due to the awareness that they are being observed. The change may be positive or negative, and depends on the situation. It is a significant threat to a research study's

external validity External validity is the validity of applying the conclusions of a scientific study outside the context of that study. In other words, it is the extent to which the results of a study can be generalized to and across other situations, people, stim ...

and is typically controlled for using

blind experiment In a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expec ...

designs. There are several forms of reactivity. The

Hawthorne effect The Hawthorne effect is a type of reactivity in which individuals modify an aspect of their behavior in response to their awareness of being observed. The effect was discovered in the context of research conducted at the Hawthorne Western Electri ...

occurs when research study participants know they are being studied and alter their performance because of the attention they receive from the experimenters. The

John Henry effect The John Henry effect is an experimental bias introduced into social experiments by reactive behavior by the control group. In a controlled social experiment if a control is aware of their status as members of the control group and is able to comp ...

, a specific form of Hawthorne effect, occurs when the participants in the control group alter their behavior out of awareness that they are in the control group. Reactivity is not limited to changes in behaviour in relation to being merely observed; it can also refer to situations where individuals alter their behavior to conform to the expectations of the observer. An

experimenter effect The observer-expectancy effect (also called the experimenter-expectancy effect, expectancy bias, observer effect, or experimenter effect) is a form of reactivity in which a researcher's cognitive bias causes them to subconsciously influence th ...

occurs when the experimenters subtly communicate their expectations to the participants, who alter their behavior to conform to these expectations. The

Pygmalion effect The Pygmalion effect, or Rosenthal effect, is a psychological phenomenon in which high expectations lead to improved performance in a given area. The effect is named for the Greek myth of Pygmalion, the sculptor who fell so much in love with the ...

occurs when students alter their behavior to meet teacher expectations. Reactivity can also occur in response to self-report measures if the measure is elicited from research participants during a task. For example, both confidence ratings and judgments of learning, which are often provided repeatedly throughout cognitive assessments of learning and reasoning, have been found to be reactive. In addition there may be important individual differences in how participants react to a particular self-report measure. Espeland & Sauder (2007) took a reactivity lens to investigate how rankings of educational institutions change expectations and permeate institutions. These authors investigate the consequences, both intended and unintended, of such public measures. A common solution to reactivity is

unobtrusive research Unobtrusive research (or unobtrusive measures) is a method of data collection used primarily in the social sciences. The term "unobtrusive measures" was first coined by Webb, Campbell, Schwartz, & Sechrest in a 1966 book titled ''Unobtrusive Measur ...

that can replace or augment reactive research. Unobtrusive research refers to methods in which the researchers are able to obtain information without interfering in the research itself. Results gathered from unobtrusive methods tend to have very high test-retest reliability.

References

{{reflist Personality traits

See also

References