Nuisance Variable

Nuisance variable is an unwanted factor which may affect the dependent variable in an experiment. Examples of this type of extraneous variable (hyperlink) include environmental conditions such as noise and temperature and participant characteristics such as mood swings and physical health.

For instance, an experiment which seeks to find out the effect of chocolate on memory performance is conducted in the laboratory. However, some of the participants were exposed to loud noise due to a construction work outside the building. This nuisance variable lessened the concentration of some of the participants during the procedures. Hence, the validity of the results is questionable.