What is the threat to the internal validity of an experiment in which it is unclear whether natural changes and/or personal development led to a given experimental outcome?

Question

Quizplus · Accepted Answer

The threat to internal validity in this case is maturational effects, which refers to the changes that occur naturally over time or due to personal development. If it is unclear whether the experimental outcome was due to the manipulation of the independent variable or simply due to natural changes, it becomes difficult to draw accurate conclusions about the effect of the independent variable on the dependent variable.

What Is the Threat to the Internal Validity of an Experiment