1. When making inferences about means of single samples, the observed value of the sample statistic is

2. True/False: Other things being equal, the critical value for a directional test is the critical value for a nondirectional test.

3. What would be the preferred statement of the null hypothesis for a nondirectional two-dependent-samples test for means?

4. Suppose that a researcher is interested in the effects of different doses of caffeine on the amount of time that it takes subjects to solve a puzzle. What is the dependent variable?

5. True/False: tobs for dependent samples will always be larger than tobs for independent samples.

6. The critical value of a statistic marks the ___ of the rejection region.

7. True/False: The second step in hypothesis evaluation is to set the criterion for rejecting the null.

8. The nondirectional alternative hypothesis for a two-independent-samples test for means is

9. True/False: The samples in a repeated-measures design are independent samples. In other words, they are not statistically related to each other.

10. True/False: A difference score is a subject's score in one condition subtracted from any other subject's score in the same condition.

11. True/False: The sample statistic for the two-independent-sample t-test is ?1 - ?2.

12. True/False: If the observed value of our test statistic for the two-independent-sample t-test is tobs = 2.05, and our critical value is tcv = 2.262, we would reject the null hypothesis.

13. True/False: The pooled variance is the unweighted average of two (or more) means.

14. True/False: If the observed value of the sample statistic lies in the rejection region, we fail to reject the null hypothesis.

15. True/False: If we have reason to predict that a particular treatment will increase scores in a population where ? = a, the alternative hypothesis will be H1: ?

16. True/False: The alternative hypothesis for a directional, two-dependent-samples test for means can be written as H1: ?D > 0.

17. True/False: The number of degrees of freedom for the t?statistic for two independent samples is n1 - n2 + 2.

18. True/False: The observed value of a sample statistic is the beginning of the rejection region.

What do these symbols mean?

1.