A Researcher Examines a Program Looking at the Effects of Mentoring

Multiple Choice

A researcher examines a program looking at the effects of mentoring on poor readers' reading achievement. He looks at two different schools. One serves as the control and the other the experimental group. Both schools had reading achievement that was around the 50th percentile. During the time that the mentoring program is in place in the experimental group, a statewide reading initiative is started in randomly selected schools. The experimental, but not the control school is involved in the statewide reading initiative. At the end of the year, the experimental group does better than the control. From the information presented above, a likely threat to the internal validity of the study is:

A) Selection by mortality interaction
B) Mortality
C) Selection-history effect
D) Selection-maturation effect