Which of the following can threaten the internal validity of a within subjects design?
A) practice effects
B) carry over effects
C) fatigue effects
D) any of the above

Question

Quizplus · Accepted Answer

All of these factors (practice effects, carry over effects, and fatigue effects) can threaten the internal validity of a within subjects design. Practice effects refer to the improvement in performance that occurs simply as a result of repeated exposure to the task at hand. Carry over effects occur when the effects of one condition carry over into subsequent conditions, possibly due to order effects or changes in the participant's state. Fatigue effects refer to the decline in performance that may arise due to the repeated nature of the task. All three of these factors can pose a threat to the internal validity of a within subjects design by confounding the effects of the independent variable being studied.

Which of the Following Can Threaten the Internal Validity of a Within