A researcher tested a group of students first time in second grade and the second time in the middle of the third grade. The second test indicated significant improvement, but after reviewing the test scores the researcher became concerned that he could not be sure whether the scores were a result of the treatment or a result of the students' having gained more life experience in a year-and-a-half. What threat to internal validity is this researcher worried about?
A) Maturation
B) Testing
C) Differential selection
D) Instrumentation

Question

Quizplus · Accepted Answer

Maturation refers to the natural development and changes that occur in participants over time, which could affect the outcome of the study independently of any treatment. The researcher is concerned that the improvement in test scores might be due to the students' natural growth and increased life experience over the year-and-a-half period, rather than the treatment itself.

A Researcher Tested a Group of Students First Time in Second