The idea that an interviewer may change his behavior when interviewing respondents in the afternoon because of a fatigue effect is the basis of which extraneous experimental factor?
A)Instrument variation
B)Mortality
C)Testing effects
D)History
E)Regression to the Mean

Question

Quizplus · Accepted Answer

Instrument variation refers to changes in the measurement instrument or process, such as an interviewer's behavior, which can affect the results. Fatigue affecting an interviewer's behavior is an example of instrument variation.

The Idea That an Interviewer May Change His Behavior When