Reactive Arrangements

Reactive arrangements are an example of a threat to the internal validity of a research design. Reactivity occurs when the results of an experiment are due, at least in part, to behaviors of participants that artificially result from their participation in the experiment. Thomas D. Cook and Donald T. Campbell and colleagues, in their works defining threats to validity in research design, distinguish between artifacts due to the use of measures in a study and other reactions that occur because participants are aware that they are in a study. When these reactions become a functional part of the treatment or independent variable, then reactive arrangements are present.

Reactivity has occurred when the “meaning” of a treatment includes the human reactions to being in a study. Reactions ...