An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.
Which of the following tests would have been the most appropriate for this design?
A) chi-square(s)
B) correlation(s)
C) t -test(s)
D) multiple regression

Question

Quizplus · Accepted Answer

The most appropriate test for this design would be a paired samples t-test, as the instructor is comparing the performance of the same group of students under two different conditions (using different textbooks). The t-test would allow her to determine if the difference in means between the fall and spring semesters (for both the final grades and student evaluations) is statistically significant, and if so, to what degree of confidence. Chi-squares and correlations would not be appropriate tests for this design, as there are no categorical variables or relationships being studied. Multiple regression would also not be appropriate, as there is only one independent variable (textbook used) being manipulated in this study.

An Instructor in Introductory Psychology Wanted to Know If the Textbook