Clarifying the Concepts
Calculating the Statistics
Identify critical t values for each of the following tests:
Assume 8 participants completed a mood scale before and after watching a funny video clip.
The following are scores for 8 students on two different exams.
| Exam I | Exam II |
|---|---|
| 92 | 84 |
| 67 | 75 |
| 95 | 97 |
| 82 | 87 |
| 73 | 68 |
| 59 | 63 |
| 90 | 88 |
| 72 | 78 |
The following are mood scores for 12 participants before and after watching a funny video clip (higher values indicate better mood).
| Before | After | Before | After |
|---|---|---|---|
| 7 | 2 | 4 | 2 |
| 5 | 4 | 7 | 3 |
| 5 | 3 | 4 | 1 |
| 7 | 5 | 4 | 1 |
| 6 | 5 | 5 | 3 |
| 7 | 4 | 4 | 3 |
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Consider the following data:
| Score 1 | Score 2 | Score 1 | Score 2 |
|---|---|---|---|
| 45 | 62 | 15 | 26 |
| 34 | 56 | 51 | 56 |
| 22 | 40 | 28 | 33 |
| 45 | 48 |
Consider the following data.
| Score 1 | Score 2 |
|---|---|
| 23 | 16 |
| 30 | 12 |
| 28 | 25 |
| 30 | 27 |
| 14 | 6 |
Assume we know the following for a paired-
Assume we know the following for a paired-
Applying the Concepts
t tests and retail: Many communities worldwide are lamenting the effects of so-
Paired-
| Player | 2007– |
2008– |
|---|---|---|
| Elias | 20 | 31 |
| Zajac | 14 | 20 |
| Pandolfo | 12 | 5 |
| Langenbrunner | 13 | 29 |
| Gionta | 22 | 20 |
| Parise | 32 | 45 |
Paired-
Attitudes toward statistics and the paired-
Paired-
| Dress Purchase | Wedding Day |
|---|---|
| 163 | 158 |
| 144 | 139 |
| 151 | 150 |
| 120 | 118 |
| 136 | 132 |
| 158 | 152 |
| 155 | 150 |
| 145 | 146 |
Putting It All Together
Hypnosis and the Stroop effect: In Chapter 1, you were given an opportunity to complete the Stroop test, in which color words are printed in the wrong color; for example, the word red might be printed in the color blue. The conflict that arises when we try to name the color of ink the words are printed in but are distracted when the color word does not match the ink color increases reaction time and decreases accuracy. Several researchers have suggested that the Stroop effect can be decreased by hypnosis. Raz, Fan, and Posner (2005) used brain-
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Political bias in academia and a paired-
The American professoriate contains a disproportionate number of people with liberal political views. Is this because of political bias or discrimination?…We sent two emails to directors of graduate study in the leading American departments of sociology, political science, economics, history, and English. The emails came from fictitious students who expressed interest in doing graduate work in the department…We analyze responses received in terms of frequency, timing, amount of information provided about the department, emotional warmth, and enthusiasm toward the student. (p. 1)
One of the fictional emails was from a fictional student who mentioned working on the presidential campaign of John McCain, a well-