A researcher was interested in examining the different levels of aggression shown by college students and prisoners with life sentences. Aggression was measured by surveys given during one session. Which analysis should the researcher perform on the mean aggression scores of the groups?
a. related means t test
b. independent means t test
c. correlation
d. regression
Question 2Using the conservative test in which variances were not pooled that was described in the text, on how many degrees of freedom would the t test on groups of 65 and 21 participants be based?
a. 65 1 = 64 df
b. 21 1 = 20 df
c. 65 + 21 2 = 84 df
d. (65 + 21) 2 = 43 df
Question 3In which of the following cases is it most useful to pool the variances?
a. s12 = 7.3, N1 = 15 and s22 = 8.1, N2 = 15
b. s12 = 7.3, N1 = 15 and s22 = 52.3, N2 = 6
c. s12 = 8.4, N1 = 13 and s22 = 12.1, N2 = 19
d. none of the above
Question 4An important reason for using random assignment in a study with independent groups is to
a. prevent any systematic differences between groups on extraneous variables.
b. be able to generalize to broader populations.
c. rule out competing interpretations of any differences we find.
d. a and c
Question 5If we built on Doob and Gross's study of horn-honking behavior to compare the time it takes for people to honk at an older car versus the time to honk at an expensive newer car, we could set it up as
a. an independent sample design.
b. a repeated measures design.
c. neither a nor b
d. It could be designed either way, depending upon our needs.