Use the Guidelines to Evaluate the Study

Multiple Choice

Use the guidelines to evaluate the study. From the information given, what is the biggest flaw in the study?
-An educational researcher wishes to compare the effectiveness of two different math textbooks. She has the tenth graders at one school use the first book for one year and the tenth graders at another
School use the second textbook for one year. At the end of the year, she gives the same math test to
Both classes and compares the results.

A) The setting
B) Selection bias
C) Participation bias
D) The source
E) Confounding variables