Suppose a researcher is performing an experiment on children. She tests the children on one level of the independent variable at the beginning of the school year, but cannot return to test the second level until mid-April, when the school year is almost completed. What threat to internal validity may be a problem?
A) History
B) Selection bias
C) Maturation
D) Experimenter bias

Question

Quizplus · Accepted Answer

Maturation is a threat to internal validity in this case, as the children may have naturally matured and developed over the course of the school year, independent of any manipulation of the independent variable. This could potentially confound the results of the experiment when comparing the two levels of the independent variable. The other options (history, selection bias, experimenter bias) are not as relevant to this specific situation.

Suppose a Researcher Is Performing an Experiment on Children