A professor wants to determine the best way to present an important topic to his class. He has the following three choices: he can lecture, he can lecture plus assign supplementary reading, or he can show a film and assign supplementary reading. He decides to do an experiment to evaluate the three options. He solicits 15 volunteers from his class and randomly assigns 5 students to each of the three conditions. The students were subsequently tested on the material. The following scores (percentage correct on the test) were obtained:
LECTURE Lecture + Reading Film + Reading
92 86 81
86 93 80
87 97 72
76 81 82
80 94 83