Choosing a Test

  

Goodness of Fit Chi-square

One Category

Contingency Table Chi-square

Two Categories

Categorical

See next slide

Continuous

Type of Dependent Variable

Choosing a Procedure

Cont.

Correlation

Degree of Relationship

Regression

Form of Relationship

One Predictor

Multiple Regression

Two Predictors

Relationships - Continuous

See next slide

Differences - Categorical

Continuous

Choosing a Procedure

Cont.

T w o -sam p le t

In de pe nd ent

R e la te d S a m p le t

D ep e nd en t

T w o G ro u ps

A no va

In de pe n de nt G rou ps

R e pe a ted m e a su res A n o va

D e pe n d en t M e a su res

M u ltip le G ro u ps

D iffe ren ce s - C a te g orica l IV

Choosing a Procedure

21.3 Seligman, Nolen-Hoeksema, Thorton, and Thorton (1990) administered a measure of optimism to the members of a university swim team. They then had everyone swim their best event, and falsely reported that each person had done somewhat worse than they actually did. Half an hour later they had each person swim the same event again, and took as their dependent measure the ratio of the first time to the second. They hypothesized that more optimistic swimmers would maintain or better their (true) first time, whereas pessimists would feel there was little they could do and would do more poorly the second time around. (Their hypothesis was confirmed.)

21.5 Franklin, Janoff-Bulman, and Roberts (1990) looked at the long-term impact of divorce on college students' levels of optimism and trust. They compared students from divorced families and students from intact families. (Note: They found no differences on generalized trust, but children of divorced families showed less optimism about the future of their own marriages.)

21.6 Zaragoza and Mitchell (1996) showed subjects a video tape of a burglary, and then asked them many questions about what happened. Some of the questions were deliberately misleading, such as saying “At the beginning of the scene, a young man dressed in jeans, a t-shirt, and gloves entered the house. Did he enter through the door?” In fact, the young man did not wear gloves. Every subject heard some misleading statements 0 times, other misleading statements once, and still other misleading statements 3 times. The experimenters examined how often subjects later reported that the video actually included those incorrect observations. (As you might expect, the more often the statements were repeated, the more often they were reported as actually occurring.)

21.10 Pihl, Lau, and Assaad (1997) classified subjects as being generally aggressive or not-aggressive. These subjects were randomly assigned to a drunk or sober condition, given significant amounts of alcohol or juice, and were then run in a study in which they both administered and received electrical shock from a fictitious opponent. When sober, subjects in the high aggressive group administered higher shock levels than subjects in the low aggressive group. When intoxicated and highly provoked, both high and low aggressive subjects administered equal amounts of shock. It was the low aggressive subjects who increased the aggressiveness of their behavior when drunk.

21.12 Pope and Yurgelun-Todd (1996) gave a battery of standard neuropsychological tests to light and heavy users of marijuana after both had abstained from marijuana and other drugs for at least 19 hours. What analysis could they use to compare the performance of the two groups? (The results showed that “heavy users displayed significantly greater impairment than light users on attentional/executive functions.”)

21.14 Many foods and beverages, such as coffee and scotch are frequently termed “acquired tastes.” Pliner (1982) was interested in investigating whether familiarity with a flavor leads to greater approval—the “acquired-taste” phenomenon. She had 24 undergraduates taste each of four unfamiliar tropical fruit juices 0, 5, 10, or 20 times. (For each subject she randomized which juice would be tasted how many times.) Subjects were then asked to rate the degree to which they liked the taste of the juice. What statistical procedures are suitable for analyzing these data?

• 21.15 Chaffin and Imreh (2002) examined the way a 21.15 Chaffin and Imreh (2002) examined the way a professional pianist learned a difficult piece of music. professional pianist learned a difficult piece of music. Among other things, they were interested in the Among other things, they were interested in the relationship between the number of times the pianist relationship between the number of times the pianist rehearsed a specific bar of music (as the dependent rehearsed a specific bar of music (as the dependent variable) and a) the number of specific mutual variable) and a) the number of specific mutual features (across 10 dimensions) that the pianist features (across 10 dimensions) that the pianist associated with that bar, b) the number of notes per associated with that bar, b) the number of notes per bar, and c) – f) four measures reflecting location in the bar, and c) – f) four measures reflecting location in the formal structure of the music (e.g. whether it was the formal structure of the music (e.g. whether it was the first bar in a section of the piece).first bar in a section of the piece).

21.18 Most people are basically happy. Diener and Diener (1996) reported data on subjective well-being from residents of 43 countries around the world. The mean was 6.33 on a scale from 0 (most unhappy) to 10 (most happy). What would you do with data such as these?

21.19 Vasta, Rosenburg, Knott, and Gaze (1997) compared the performance of four groups of male and females subjects to Piaget’s water-level task, in which a subject looks at a partially full glass of water and then draws where the water level would be if the glass were tilted to the side. The four groups were bartenders, servers, clerical workers, and salespersons. (Contrary to previous research, bartenders and servers were best. Females were generally better than males.)

21.24 Lobel, Dunkel-Schetter, and Scrimshaw (1992) examined medical risk factors, gestational age, and the mother's emotional stress as predictors of low birthweight. How could they assess the relationship between these factors and low birthweight? (Note: Gestational age and stress predicted birthweight but not medical risks. Women who experienced daily anxiety were most likely to deliver low-birthweight babies.)

21.27 Hunt, Streissguth, Kerr, and Olson (1995) asked 14-year-olds to perform a spatial-visual reasoning task where it was possible to evaluate the amount of time each person viewed a figure before responding, and the accuracy of that response. They also obtained the amount of alcohol the child’s mother reported consuming during pregancy (14 years earlier). (Both study time and number correct were negatively correlated with alcohol consumption during pregnancy, though, as expected, the correlations were not very high.)