Grand Canyon University| PSY 550 Final Exam : Research Methods| Complete Solutions Graded A+ AlreadyChuck Wagon is very excited about the within-subjects approach. “Now I’ll never need
to run large numbers of subjects a
...
Grand Canyon University| PSY 550 Final Exam : Research Methods| Complete Solutions Graded A+ AlreadyChuck Wagon is very excited about the within-subjects approach. “Now I’ll never need
to run large numbers of subjects again,” he says. However, Chuck has forgotten that
within-subjects designs may be a) useless, b) impossible, c) confounded by order effects, or
d) impractical when excessive subject time spent in an experiment makes data inaccurate.
Give an example of each of these four objections.
Explain the pros and cons of longitudinal, cross-sectional, and sequential designs.
After watching nursery-school children, Ken Garoo wants to test the hypothesis that
some toys are more fun to play with than others. He decides to compare “fun” toys (blocks)
with “unfun” toys (stuffed animals). He also wishes to see if there is a sex difference, as
well, so sex is added as an independent variable. A) What kind of design is needed? B)
Diagram it out. C) Assuming 20 subjects are needed per cell, how many subjects are needed
for this study?
Bill Board is “lording” his SAT score over his friend, Rhoda Dendron, who took the
ACT. “You only got a 25 in math,” he chortled, “while I got a 300 in math.” Given that the
SAT has a μ of 500 and a σ of 100, and the ACT has a μ of 20 and a σ of 5, what is wrong
with Bill’s logic (give the answer in both z scores and percentile ranks)
A researcher has studied subjects’ ability to learn to translate words into Morse code. He
has experimented with two treatment conditions: in one condition, the subjects are given
massed practice; they spend 8 full hours on the task. In the other condition, subjects are
given distributed practice; they also spend 8 hours, but their practice is spread over four
days, practicing 2 hours at a time. After the practice, all subjects are given a test message to
encode; the dependent variable is the number of errors made. The researcher has matched
the subjects on intelligence. The results are in the following table. Decide which statistical
test would be appropriate, carry out the test, and evaluate the outcome. Assume a
significance level of .05 and that the direction of the outcome has not been predicted
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