Psy 230 combined Lab 6 & 7
20 points available-- PLEASE TYPE!
Comparing Between- and Within-Subject Designs
Not Humorous
10
2
1
15
7
Humorous
11
5
2
18
9
A researcher is interested in the impact of humor on memory for sentences. Scores indicate the number
of sentences out of 20 accurately recalled by participants.
1. Assume that the data are from an independent measures experiment using two separate samples,
each with n = 5 participants. Use SPSS. Do the data indicate a significant difference between the
two treatments? Use a two-tailed test with alpha = .05.
a. State the null and alternative hypotheses.
b. Indicate your decision (Retain or Reject the null hypothesis?)
c. Type a report of the results in APA format.
2. Now assume that the data are from a repeated-measures experiment using the same sample of n = 5
participants in both treatments. Calculate the difference score for each subject and conduct a t-test
for repeated measures. Do the data indicate a significant difference between the two treatments?
Again, use a two-tailed test with alpha = .05.
a. State the null and alternative hypotheses.
b. Indicate your decision (Retain or Reject the null hypothesis?)
c. Type a report of the results in APA format.
3. How do you explain the different outcomes? (Compare the mean differences obtained. Also
compare the standard errors for the two different tests.)