Paper Details
A social psychologist studying mass communication randomly assigned 82 volunteers to one of two experimental groups. Sixty-one were instructed to get their news for a month only from television, and 21 were instructed to get their news for a month only from the Internet. (Why the researcher didn’t assign equal numbers to the two conditions is a mystery!) After the month was up, all participants were tested on their knowledge of several political issues. The researcher did not have a prediction as to which news source would make people more knowledgeable. That is, the researcher simply predicted that there is some kind of difference. These were the results of the study. TV group: M = 24, S2 = 4; Internet group: M = 26, S2 = 6. Using the .01 level, what should the social psychologist conclude?
(a) Use the steps of hypothesis testing.
(b) Sketch the distributions involved.
(c) Explain your answers to someone who is familiar with the t test for a single sample, but not with the t test for independent means.
