Question

# 1) Psychologists know that people find it easier to remember items at the beginning and at...

1) Psychologists know that people find it easier to remember items at the beginning and at the end of a list of items. Suppose you think that level of education might make a difference to the tendency to remember items in the middle of the list. You randomly select two groups of subjects, with N = 10 in each group.   Participants in Group 1 have 12 years of education, and members of group 2 have 20 years of education. Which test should you use to analyze the results?

1. z test
2. single sample t test
3. independent samples t test
4. dependent samples t test

2) Most sleeping pills reduce the period of REM sleep. You want to validate the claims of a new sleeping pill, which is advertised as not affecting REM sleep at all. You randomly select a single group of people, and for one week they receive a placebo, and then for another week they receive the recommended dosage of the new sleeping pill. REM sleep is monitored in a sleep lab and the total number of minutes spent in REM are counted for each person.   The average amount of REM sleep for the placebo is then compared to the average amount of REM sleep for the sleeping pill. Which test should you use to analyze the data?

1. z test
2. single samples t test
3. independent samples t test
4. dependent samples t test

3) A t test comparing the means between two independent groups yields a p value of .02 (p = .02). What should you do about the null (H0) hypothesis?

1. Reject H0
2. Do not reject H0
3. Accept H0

4) A test measuring variability between multiple groups yields a p value less than .05 (p < .05). What should you do about the null (H0) hypothesis?

1. Reject H0
2. Do not reject H0
3. Accept H0

5) A t test comparing a person's score on a test before and after an intervention yields a p value of .08 (p = .08). What should you do about the null (H0) hypothesis?

1. Reject H0
2. Do not reject H0
3. Accept H0

6)If the null (H0) hypothesis is true, then no difference exists between populations.

1. True
2. False

7) In an ANOVA, if there is no difference between the groups, then the F ratio will approximately equal _______.

1. 0
2. 1
3. -1
4. .05

8) Arnold compares the means of three groups and calculates a value of -2.01 for the F ratio. This necessarily implies that. . .

1. the mean of the first group is the highest of the three groups
2. the mean of the third group is the highest of the three groups
3. the differences between the means are statistically significant
4. he made an error is his calculation

9) The problem with conducting multiple t-tests instead of using a post-hoc test is that you increase the risk of Type 1 errors.

1. True
2. False

10) A researcher theorizes that Freshmen spend more time studying than Sophomores, who spend more time studying than Juniors, who spend more time studying than Seniors. In conducting a one-way ANOVA on this data, what is the most appropriate way to state the null (H0) hypothesis?

1. all µs are different
2. not all µs are different
3. all µs are equal
4. not all µs are equal