When evaluating the in-service programs, you determine that the second group scored 40 on both the pretest and posttest. You also discover that teachers in the first group were given home computers one month after the program began. How would you interpret the results?
A)the change in the first group demonstrates a regression to the mean
B)the in-service training might have had some effect, but there is a serious selection by history confound here
C)the in-service training program is the only factor that could have produced the effect
D)the second group obviously didn't try, so any comparison is meaningless

Question

Quizplus · Accepted Answer

The provision of home computers to the first group introduces a confounding variable, making it difficult to attribute changes solely to the in-service training.

When Evaluating the In-Service Programs, You Determine That the Second