1 A researcher reports that stress levels among nurses are h

1. A researcher reports that stress levels among nurses are higher compared to stress levels in the general population, t(20) = 2.086, p = .05 (d = .12). Was this a one-tailed or a two-tailed test?

a)One-tailed test because the p value is equal to .05

b)Two-tailed test because the p value is equal to .05

c)It could be a one- or a two-tailed test

2. Which of the following summarizes a t test that was significant and associated with a large effect size?

a) t(22) = 3.02, p < .05, d = .36

b) t(30) = 1.03, p > .05, d = .20

c) t(60) = 1.76, p > .05, d = .45

d) t(12) = 2.95, p < .05, d = .82

3. A researcher selects a sample of 32 participants who are assigned to participate in a study with two groups. What are the degrees of freedom for this test?

a) 32

b) 30

c) 31

d) There is not enough information to answer this question.

4. Which type of error is used to compute the confidence interval for two independent samples selected from at least one population with an unknown variance?

a) standard error

b) estimated standard error

c) estimated standard error for the difference

d) estimated standard error for the difference scores

5. Two researchers (A and B) compute a two-independent sample t test. For both tests, the mean difference between the two groups is 10, but the standard error is smaller for Researcher A. Which test is more likely to result in a decision to reject the null hypothesis?

a) Researcher A.

b) Researcher B.

c) The likelihood is the same for both researchers.

d) There is not enough information to answer this question.

6. A researcher reports that the effectiveness of a new marketing campaign significantly increased sales compared with the previous campaign strategy, t(49) = 2.562, p < .05. Use eta-squared to interpret the effect size for this result.

a) 12% of the variability in marketing effectiveness can be accounted for by the new marketing strategy.

b) 12% of the standard error can be accounted for by the effectiveness of the marketing strategy.

c) Marketing effectiveness shifted 0.12 standard deviations above the mean in the population.

d) both A and B are correct

7. A researcher reports a significant mean difference in a given population. If she computes both eta-squared and omega-squared to measure the effect size, then which estimate will be the most conservative?

a) eta-squared

b) omega-squared

c) It depends on the sample size.

d) It depends on the value of the t statistic.

8. A researcher reports that the mean difference in response time to an auditory versus a visual cue is 0.83 seconds, with a pooled sample variance equal to 2.45. What is the effect size for this test using estimated Cohen\'s d?

a) d = 0.53; medium effect size

b) d = 0.53; large effect size

c) d = 0.34; small effect size

d) d = 0.34; medium effect size

Solution