The internal validity of the smoking study above is threatened by the before-measure effect.

Question

Quizplus · Accepted Answer

The before-measure effect refers to the possibility that the act of measuring participants before the experiment (in this case, their smoking habits) could have influenced their behavior during the experiment. This could threaten the internal validity of the study by creating an alternative explanation for any observed changes in smoking behavior.

The Internal Validity of the Smoking Study Above Is Threatened