The article “Computer-Assisted Instruction Augmented with Planned Teacher/Student Contacts” (J. of Exp. Educ., Winter, 1980–1981: 120–126) compared five different methods for teaching descriptive statistics. The five methods were traditional lecture and discussion (L/D), programmed textbook instruction (R), programmed text with lectures (R/L), computer instruction (C), and computer instruction with lectures

(C/L). Forty-five students were randomly assigned, 9 to each method. After completing the course, the students took a 1-hour exam. In addition, a 10-minute retention test was administered 6 weeks later. Summary quantities are given.

P-value 5 .029 a 5 .01 f 5 3.68 of six motors. The amount of motor vibration (measured in microns) was recorded when each of the 30 motors was running. The data for this study follows. State and test the relevant hypotheses at significance level .05, and then carry out a multiple comparisons analysis if appropriate.

Mean 1: 13.1 15.0 14.0 14.4 14.0 11.6 13.68 2: 16.3 15.7 17.2 14.9 14.4 17.2 15.95 3: 13.7 13.9 12.4 13.8 14.9 13.3 13.67 4: 15.7 13.7 14.4 16.0 13.9 14.7 14.73 5: 13.5 13.4 13.2 12.7 13.4 12.3 13.08