1)A Loyola University student conducted a study comparing the creativity scores of four biology and four history majors. The results were
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Biology
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History
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|
4
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7
|
|
6
|
3
|
|
3
|
5
|
|
3
|
6
|
Can you set up the formula that would be used to compute a t test? What would be the degrees of freedom? How would you compute and interpret the effect size?
2)An experimenter at the University of California at San Diego conducted a study of sex differences in nonverbal sensitivity using an independent-sample design, with 32 women and 32 men. Her results showed that the women were significantly better than the men at decoding nonverbal cues, t = 2.34, df = 62, p < .05 two-tailed, and Cohen's d = 0.594 and reffect size = .28. Suppose the experimenter added an additional 30 women and 30 men, randomly selected from the same population as the original sample. When the analysis is recalculated with the extra participants, should the new t be larger, smaller, or about the same size? Should the p value be larger, smaller, or about the same size? Should Cohen's d and the reffect size be larger, smaller, or about the same size relative to the original effect size values? Should the 95% confidence interval be wider, narrower, or about the same size?
3)A University of Pittsburgh researcher has the following two sets of data, each of which contains three independent groups. The 12 subjects in each set were randomly assigned to the groups; 4 subjects were assigned to each group. The numbers are scores on some dependent measure.
Set A:
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Group 1
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Group 2
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Group 3
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|
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2
|
5
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11
|
|
|
3
|
5
|
10
|
|
|
2
|
4
|
9
|
|
|
1
|
6
|
10
|
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Mean
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2
|
5
|
10
|
Set B:
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Group 1
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Group 2
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Group 3
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|
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9
|
11
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23
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|
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-6
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-10
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10
|
|
|
4
|
0
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-2
|
|
|
1
|
19
|
9
|
|
Mean
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2
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5
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10
|
Which set of data is likely to yield a larger F ratio in an analysis of variance? How can you be sure?
4)A University of Maine student obtains the data shown and computes the ANOVA shown His primary interest, however, is in whether the scores of the hot lunch group on average are significantly better than the average scores of the remaining three groups. How would you advise him to address his question?
(Tables are on page 3)
5)A researcher at Rochester Institute of Technology asks 10 engineering students each from the freshman, sophomore, junior, and senior classes whether they plan to attend graduate school. The results are:
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Frosh
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Sophs
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Juniors
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Seniors
|
|
Want advanced degree
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7
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6
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3
|
1
|
|
Want out of school
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3
|
4
|
7
|
9
|
How many degrees of freedom would the chi-square for this table have? How should the researcher calculate the expected frequencies? What is the nature of the relation between year in college and wanting an advanced degree
Tables
Table 14.2 Data for ANOVA Based on Results A
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Group 1 Zero
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Group 2 Milk
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Group 3 Vitamins
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Group 4 Hot lunch
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|
|
|
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8
|
10
|
13
|
17
|
|
|
10
|
12
|
15
|
19
|
|
|
12
|
14
|
17
|
21
|
|
M k
|
10
|
12
|
15
|
19
|
| |
Table 14.3 Summary ANOVA for Results
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Source
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SS
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df
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MS
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F
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p
|
|
Between conditions
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138
|
3
|
46
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11.50
|
.003
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|
Within conditions
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32
|
8
|
4
|
|
|