GCU PSY550 Week 8 Final Exam Latest 2019 September

PSY550
Research Methods

Week 8 Final
Exam

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.

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

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

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

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

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

4After
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?

5Bill 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.