Two classes of students at different schools are closely matched on IQ scores. One class is being taught with the standard method and the other class is being taught with a new technique. The two classes are then to be compared on scores from a standardized test at the end of the year.
A) since the classes are matched, any difference at year's end is due to the teaching technique
B) even though matched on IQ scores, the classes may not be equivalent on many other variables
C) because there was no pretest, no valid comparisons can be made
D) maturation is a major confounding variable in this study

Question

Quizplus · Accepted Answer

Even though the classes are matched on IQ scores, they may differ in other important ways that could affect their performance, such as motivation, socioeconomic status, or prior knowledge, making it difficult to attribute differences in test scores solely to the teaching method.

Two Classes of Students at Different Schools Are Closely Matched