Two biology instructors set out to evaluate the effects of discovery-based teaching compared to the standard lecture-based teaching approach in the laboratory.13 The standard lecture-based approach provided a list of instructions to follow at each step of the laboratory exercise, whereas the discovery-based approach asked questions rather than providing directions, and used small group reports to decide the best way to proceed in reaching the laboratory objective. One evaluation of the techniques involved written appraisals of both techniques by students at the end of the course. The comparison of the number of positive and negative responses for both techniques is given in the following table.

a. Is there a significant difference in the proportion of positive responses for each of the teaching methods? Use α =.05. If so, how would you describe this difference?
b. What is the approximate p-value for the test in part a?

Negative EelEauations Total Group Evaluations Discovery Control 37 31 48 17