Exam Review 2 - RM Flashcards
Dr. Scott finds a correlation of .80 between self-esteem and confidence. Dr. Scott claims that the result is
due to an outlier with an extremely high self-esteem score and an extremely high confidence score. If
Dr. Scott’s claim is true, what is a more believable value of the correlation once the outlier is removed?
.50
Researchers asked college students whether they had ever taken any hallucinogenic drugs (yes or no). All the students were then given a test of creativity. Students who admitted having taken the drugs scored higher on the test of creativity on average. The researchers concluded that hallucinogenic drugs foster creative abilities in young adults.
what is the best description of the
conclusion?
Basically incorrect because they cannot infer causation using this method
Which of the following will probably be plotted as a bar graph rather than a scatterplot?
People who drink score higher on a measure of fatigue than people who do not drink
Suppose we predicted divorce (1=yes, 0=no) from number of children and couple’s average
age in a representative sample of N=500. We find the following results: beta for children = .10
(n.s.) and beta for age = .25* (* p < .05). What is the interpretation?
Age predicts divorce controlling for children, but children does not after controlling for age.
Children with unusual names are more likely to have delinquency records as adolescents
because they got teased more, and the teasing makes them act out:
Mediator
Having a cognitively demanding job is associated with cognitive benefits in later years, but
only among men, not among women.
Moderator
In multiple regression, two or more variables are considered simultaneously. If minutes of
recess has a significant beta in predicting behavior probs while controlling for predictor 2
(proportion of free lunches), we can conclude:
School lunch does not explain the effect of minutes of recess
A Research Methods teacher wants to know whether a computer tutor is helpful in learning experimental design. She allows up to half the class to volunteer to use the tutor (first come, first served). At the end of the class all the students take the same exam. The computer tutored group does significantly better on the exam. The threat to internal validity is \_\_\_\_\_
Selection
Dr. B. wants to test whether exercising for 20 minutes improves mood. She randomly assigns
half the students to an exercise condition and half to no exercise condition. Afterward, she
gives them a measure of mood. This is an example of a ____ design:
Posttest only
-Mr. Smith- Drivers Ed instructor
-Tested his class on safety attitudes, then gave a
lecture on the importance of vigilance (‘watch
out for the other guy’)
-Tested the students again 1 week later
-Students had safer attitudes after the lecture
-During the week between tests, a wrong way
driver killed some of the students at that school
in a collision.
The threat described in Mr. Smith’s study is
History Threat
Dr. Swanson tests fitness in his Phys Ed class using an old stopwatch. He clocks each runner around a track (440 yards). At the end of the semester, he does it again and finds that people are faster on average. But the more the stopwatch is wound, the slower it goes. A major threat to the study’s internal validity is
Instrumentation
Dr. Swanson is testing his new weight loss program. He randomly assigns participants to either
a control (wait list) condition or a rigorous exercise condition. He finds that the exercise group
weighs less on average at the end of the study, but unlike the control condition, most of the
people with the highest BMIs in the exercise condition quit the study before the end. A major
threat to the study’s internal validity is
Attrition
Dr. Z runs 3 x 2 x 2 independent groups factorial ANOVA with 10 participants per cell. How
many participants does he need?
120
Dr. Smith runs 3 x 2 x 2 between factorial ANOVA with 10 participants per cell. How many
independent variables are there?
3
