Match each the situation that illustrates it with type of extraneous variable that threatens the internal validity of an experiment.
-A group of students who fall below the 15th percentile on a reading achievement test earns higher scores on the posttest following an experimental treatment, whereas a group of students who fall above the 85th percentile earns lower scores on the same posttest following the same experimental treatment.
A) History
B) Maturation
C) Testing
D) Experimental treatment diffusion
E) Statistical regression
F) Differential selection
G) Experimental mortality

Question

Quizplus · Accepted Answer

This situation illustrates statistical regression, where extreme scores on a pretest tend to move (regress) toward the mean (average) on a posttest. The lower-scoring group's scores improve, and the higher-scoring group's scores decrease, which is typical of statistical regression to the mean.

Match Each the Situation That Illustrates It with Type of Extraneous