Conceptual Questions

1. What is the difference between repeated and independent measures t test? How would you know which formula to use on a test (what could you put on a cheat sheet to know which formula to use?
2. What is pooled variance and why do we have to pool the variance?
3. What are the advantages of repeated measures compared to independent measures? What are the disadvantages of repeated measures?
4. What is indicated by a large variance for a sample of difference scores?

Math

1. If a journal reported "t(22) = 9.82, p < .05"
2. 1. How many people participated if a repeated measures study?
   2. How many people participated if an independent measures study?

1. Stanley Milgram (1974) examined if those who were given a direct order to shock another individual would do so or not. He had one sample (n = 12) receive the orders directly from a person in the same room, which led to an average shock score of M = 55 and s² = 8. In a second condition, a sample of people (n = 12) received orders from a telephone which led to an average shock score of M = 52 and s² = 4 with pooled variance equal to 6.
   1. Using all 6-steps of hypotheses testing, examine if there was a significant difference between the two conditions ( = .01, 95% Confidence Intervals).

7. For my thesis [YAWN!] (Story, 2000), I examined if a flyer discussing the benefits of recycling would cause residents to recycle more material. I selected a sample 25 households for my study. I found that the average change in the amount of material they recycled was (Mean difference = 4.7). The variance of their scores was 64.

1. 1. Using the 6-steps of hypothesis testing (alpha = .05, 99% CI), determine if recycling significantly increased or not.