Question 3

Explain the difference between a matched-subjects design and a repeated-measures design.

Question 4

A researcher conducts an experiment comparing two treatment conditions and obtains data with 10 scores for each treatment condition.

1. If the researcher used and independent-measures design, how many subjects participated in the experiment?
2. If the researcher used a repeated-measures design, how many subjects participated in the experiment?
3. If the researcher used a matched-subjects design, how many subjects participated in the experiment?

Question 22: A researcher for a cereal company wanted to demonstrate the health benefits of eating oatmeal. A sample of 9 volunteers was obtained and each participant ate a fixed diet without any oatmeal for 30 days. At the end of the 30 -day period, cholesterol was measured for each individual. Then the participants began a second 30-day period in which they repeated exactly the same diet except that they added 2 cups of oatmeal each day. After the second 30-day period, cholesterol levels were measured again. The scores for the 9 participants are as follows: \(0,-2,-11,-15,-12,+3,-9,-9,-8\) (a negative scores indicates a decrease in cholesterol level).

Are the data sufficient to demonstrate a significant change in cholesterol level after 30 days with an oatmeal diet? Use a two-tailed test with \(\alpha=.05\).

Question 2 3

A variety of research results suggest that visual images interfere with visual perception. In one study, Segal and Fusella (1970) had participants watch a screen, looking for brief presentations of a small blue arrow. On some trials, the participants were also asked to form a mental image (for example, imagine a volcano). The results show that participants made more errors while forming images than while not forming images. Data similar to the Segal and Fusella results are as follows. Do the data indicate a significant difference between the two conditions? Use a two-tailed test with = 05.

Participant Errors with image Errors without image

A 14 4

B 9 2

C 12 10

D 7 8

E 10 6

F 8 6

G 9 4

SPSS Assignment 1

Please complete Week 9 Assignment 1 in the file SPSS Assignments.doc (pp. 21–25). This assignment walks you through the process of merging data from two SPSS tables into one SPSS table for analytic purposes. You will need to complete this assignment before you do SPSS Assignment 2. No report is necessary for Assignment 1.

SPSS Assignment 2

The Oak Harbor School used the Dumbarton University Math Battery (DUMB) to test the math achievement of the two 6th-grade sections. The principal was able to obtain the student scores from an administration of the same test the prior year. Using these earlier scores as a pre-test, she would like to know if the students have demonstrated significant growth in achievement.

• Use the data table created in Week 9 Assignment 1.
• State the null and alternative hypotheses for testing the means of these related samples.
• Conduct a two-tailed t test for related (related/repeated) samples at the .05 level.
• Copy or copy object and paste relevant output from the statistical test.
• State whether or not the null hypothesis is accepted or rejected based on the results of the statistical test. Use the conventions described by Gravetter and Wallnau on pages 282–285 to present your report.
• In a brief paragraph, explain what your findings mean in relation to the experiment discussed in the problem.

Solution: We need to test

Using SPSS, the following results are obtained:

The t-statistics is t = 6.890, and the corresponding p-value for 33 degrees of freedom p < 0.0001, which means that the null hypothesis is rejected. This means that the sample provides enough evidence to claim that there is a significance mean difference between the pre and post test scores.

Price: $14.69

Solution: The downloadable solution consists of 6 pages, 869 words and 2 charts.
Deliverable: Word Document