Exercise 12.1: Trying to Determine the Effects of Classroom Activity

1. A college professor wants to determine if holding discussions in class, rather than lecturing all the time, improves student learning. He teaches two sections of an introductory course and decides, for a semester, to have one section engage in discussions twice a week while the other would have only lectures. He calls this an experiment, and when the section holding discussions has higher grades on both the midterm and final exams, he declares that class discussions improve learning. Has he conducted an experiment? What are some possible sources of error in the conclusions he has drawn?



2. A researcher designs a "classic" experiment and discovers that 6th grade students in one classroom who were assigned to an experimental group using computers were much better at correctly solving arithmetic problems as compared to the students in a control group in the classroom that did not use computers. Because the study was conducted in a single classroom with only 30 students, the findings cannot be generalized to other situations. Given that limitation, is there any value to completing the research at all?