PSY550 Week 8 Final Exam Latest 2019 January Question # 00599425 Subject: Education Due on: 03/13/2019 Posted On: 03/13/2019 09:10 AM Tutorials: 1 Rating: 4.8/5

PSY550 Research
Methods

Week 8 Final Exam

1 For each of the following examples, explain whether the
researcher has made a correct decision or has made a Type 1 or Type 2 error.
Explain why.

Dr. G rejects the null hypothesis although the independent
variable had no effect.

Dr. R rejects the null hypothesis when it is false.

Although the independent variable had an effect, Dr. E does
not reject the null hypothesis

2 Explain the value of reversal designs (ABA designs) in
single-case research.

3 Explain how a one-way analysis of variance works. How do
you use between- and within-group variability?

4 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?

5 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 ? of 500 and a ? of 100,
and the ACT has a ? of 20 and a ? of 5, what is wrong with Bill’s logic (give
the answer in both z scores and percentile ranks).

6 Describe a two-matched groups design. How is the matching
done?

7 Chuck 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.

8 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.

9 Explain the pros and cons of longitudinal,
cross-sectional, and sequential designs.

10 Define the term quasi-experiment and discuss the pros and
cons of this research method.