Quizzes
1. The two properties about a set of measurements of a dependent variable that we are most interested in describing are:
| a. | frequency and average. | |
| b. | average and correlation. | |
| c. | central tendency and dispersion. | |
| d. | histograms and polygons. | |
2. The ________________ is the sum of all the scores divided by the number of scores.
| a. | median | |
| b. | mean | |
| c. | mode | |
| d. | standard deviation | |
3. The generally preferred measure of central tendency is usually the
| a. | range |
| b. | mean |
| c. | standard deviation |
| d. | Median |
4. Which of the following is the most useful descriptive statistic for measuring dispersion?
| a. | Range | |
| b. | Variance | |
| c. | mean deviation | |
| d. | standard deviation | |
5. The standard deviation is
| a. | the square of the variance. | |
| b. | the square root of the variance. | |
| c. | smaller than the mean. | |
| d. | the difference between the highest and lowest scores. | |
6. If the mean I.Q. is 100 and the standard deviation of I.Q. scores is 15, then an I.Q. of 130 will have a z score (or standard score) of
| a. | 1.00 | |
| b. | 0.00 | |
| c. | 2.00 | |
| d. | -2.00 | |
7. Inferential statistics allow you to decide whether a difference between the experimental and the control group is due to _______________ or ________________.
| a. | manipulation; chance | |
| b. | manipulation; experimental error | |
| c. | sampling error; independent variable | |
| d. | independent variable; experimental error | |
8. The null hypothesis suggests that the two samples come from ___________ distribution(s), and the experimental hypothesis suggests that the two samples come from _____________ distribution(s).
| a. | different; different | |
| b. | different; the same | |
| c. | the same; different | |
| d. | the same; the same | |
9. The power of a statistical test refers to its ability to
| a. | reject false null hypotheses. | |
| b. | reject false experimental hypotheses. | |
| c. | reject true null hypotheses. | |
| d. | reject true experimental hypotheses. | |
10. Simple analysis of variance is used in designs having
| a. | one independent variable | |
| b. | more than one independent variable | |
| c. | more than one independent variable (IV) but less than four IVs | |
| d. | more than one dependent variable | |
11. The number of participants in a study is denoted by
| a. | s. | |
| b. | n. | |
| c. | z. | |
| d. | r. | |
12. A _____________ is a complete set of measurements.
| a. | sample | |
| b. | population | |
| c. | random sampling | |
| d. | parameter | |
13. _____________ is one way of ensuring that a sample is representative of the population.
| a. | The two-tailed test | |
| b. | The between-subjects design | |
| c. | The sign test | |
| d. | Random sampling | |
14. If we conduct an experiment on average young, white, college males, inferential statistics allow us to generalize to the population of
| a. | average young, white, college males. | |
| b. | college male students. | |
| c. | college students. | |
| d. | young adults. | |
15. If we apply an alpha level of .05, and there really is no effect of the experimental manipulation, then one should make a Type I error
| a. | 5% of the time. | |
| b. | 10% of the time. | |
| c. | 15% of the time. | |
| d. | 95% of the time. | |
16. Which of the following would be considered the most conservative alpha level?
| a. | .01 | |
| b. | .05 | |
| c. | .10 | |
| d. | .15 | |
17. The prediction that alcohol slows reaction time is
| a. | nondirectional. |
| b. | directional. |
| c. | semidirectional. |
| d. | partially directional. |
18. Two-tailed tests are _______________ conservative and ______________ powerful than one-tailed tests.
| a. | less; less | |
| b. | less; more | |
| c. | more; less | |
| d. | more; more | |
19. The _____________ indicates the number of scores that are free to vary.
| a. | U | |
| b. | degrees of freedom | |
| c. | magnitude of effect | |
| d. | point biserial | |
20. The ____________ is used to analyze the results when there are more than two groups.
| a. | t-test | |
| b. | z-test | |
| c. | analysis of variance | |
| d. | none of the above | |
21. The __________ maintains that two conditions do not differ.
| a. | experimental hypothesis | |
| b. | level of confidence | |
| c. | law of effect | |
| d. | null hypothesis | |
22. A conservative statistical test is one that
| a. | minimizes both Type I and Type II errors. | |
| b. | minimizes Type I errors, but increases the chance of Type II errors. | |
| c. | minimizes Type II errors, but increases the chance of Type I errors. | |
| d. | increases the chance of both Type I and II errors. | |
23. What are inferential statistics used for?
| a. | summarize the mean and standard deviation of the data | |
| b. | estimate if differences between groups are by chance | |
| c. | describe the data from 2 unrelated groups | |
| d. | describe the relationship within a set of data | |
24. Descriptive statistics are used to:
| a. | compare the significance of the difference between 2 data sets | |
| b. | test the difference between the means | |
| c. | describe the observations | |
| d. | describe the type one error in an experiment | |
25. Which of the following is not a characteristic of the normal curve:
| a. | bell-shaped |
| b. | represents 100% of the scores under the curve |
| c. | 100 is at the center |
| d. | allows us to determine rank |