## Description

**PSY 520 Topic 6 Exercise Chapter 16, 17 and 18**

**16.9** Given the aggression scores below for Outcome A of the sleep deprivation experiment, verify that, as suggested earlier, these mean differences …. seriously by testing the null hypothesis at the .05 level of signiﬁcance. Use the computation formulas for the various sums of squares and summarize results with an ANOVA table.

**16.10** Another psychologist conducts a sleep deprivation experiment. For reasons beyond his control, unequal numbers of subjects occupy the different groups. (Therefore, when calculating in SS between and SS within, you must adjust the denominator term, n , to reﬂect the unequal numbers of subjects in the group totals.)

(a) Summarize the results with an ANOVA table. You need not do a step-by-step hypothesis test procedure. ΣT2n

(b) If appropriate, estimate the effect size with h2.

(c) If appropriate, use Tukey’s HSD test (with –n 5 4 for the sample size, n) to identify pairs of means that contribute to the signiﬁcant F , given that –X0 5 2.60, –X24 5 5.33, and –X48 5 9.50.

(d) If appropriate, estimate effect sizes with Cohen’s d.

(e) ….results would be reported in the literature, given sample standard deviations of s 0 5 2.07, s 24 5 1.53, and s 48 5 2.08. psy 520 topic 6 exercise

**16.12** For some experiment, imagine four possible outcomes, as described in the following ANOVA table.

(a) How many groups are in Outcome D?

(b) Assuming groups of equal size, what’s the size of each group in Out-come C?

(c) Which outcome(s) would cause the null hypothesis to be rejected at the .05 level of signiﬁcance?

(d) Which outcome provides the least information about a possible treatment effect?

(e) Which outcome would be the least likely to stimulate additional research?

(f) Specify the approximate p -values for each of these outcomes.

**16.14** The F test describes the ratio of two sources of variability: that for subjects treated differently and that for subjects treated similarly. ….the t test for two independent groups can be viewed likewise psy 520 topic 6 exercise?

**17.6** Return to the study ﬁrst described in Question 16.5 on page 336, where a psychologist tests whether shy college students initiate more eye contacts with strangers because of training sessions in assertive behavior. Use the same data, but now assume that eight subjects, coded as A, B, . . . G, H, are tested repeatedly after zero, one, two, and three training sessions…. Summarize the results with an ANOVA table. Short-circuit computational work by using the results in Question 16.5 for the SS terms, that is, SS between 5 154.12, SS within 5 132.75, and SS total 5 286.87.

(b) Whenever appropriate, estimate effect sizes with □ 2 p and with d, and conduct Tukey’s HSD test.

(c) Compare these results with repeated measures with those in Question 16.5 for independent samples.

**17.7** Recall the experiment described in Review Question 16.11 on page 314, where errors on a driving simulator …. for subjects whose orange juice …..with controlled amounts of vodka.

(a) Summarize the results in an ANOVA table. If you did Review Question 16.11 and saved your results, you can use the known values for SS between , SS within , and SS total to short-circuit computations psy 520 topic 6 exercise.

(b) If appropriate, estimate the effect sizes and use Tukey’s HSD test.

17.8 While analyzing data, an investigator treats each score as if it ….by a different subject even though, in fact, scores were repeated measures. What effect, if any, would this mistake probably have on the F test if the null hypothesis were

**18.8** For the two-factor experiment described in the previous question, assume that, as shown, mean bar press rates of either 4 or 8 are identiﬁed with three of the four cells in the 2 X 2 table of outcomes.

**18.11** In what sense does a two-factor ANOVA use observations more efﬁciently than a one-factor ANOVA does?

**18.12** A psychologist employs a two-factor experiment to study the combined effect of sleep deprivation and alcohol consumption on the performance of automobile drivers. psy 520 topic 6 exercise Before the driving test, the subjects go without sleep for various time periods and then drink a glass of orange juice laced with controlled amounts of vodka…..

**(TWO VERSIONS)**