# Two-Way ANOVA

SPSS Homework 4 Instructions

Two-Way ANOVA

Part One: Note: For the two-way ANOVA, you will be expected to create a line graph as covered in the SPSS tutorial in the Course Content (and not a boxplot as in the textbook). This applies to future cumulative questions as well.

Green & Salkind: Lesson 26, Exercises 1, 4, 5, 6, 7, and 8

The following helpful tips are numbered to correspond with the exercise number to which they refer (a dash indicates that no tips are needed):

1. Instead of identifying these values on your output, as the text states, please write them into your Microsoft Word file as written answers for #1 a, b, c, and d. (2 pts for output; 2 pts. each for a–d)

4. Produce a line graph instead of a boxplot for this problem. Follow directions in course SPSS tutorial for setting up a line graph. (2)

5. ——- (2)

6. ——- (2)

7. Write a current APA-style Results section based on your analyses. All homework “Results sections” must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in Current APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (2)

8. Produce a line graph instead of a boxplot for this problem, and for Two-way ANOVA’s in general in the course. Follow directions in course SPSS tutorial for setting up a line graph. (2)

Part Two:

1. A health psychologist is interested in the effects of exercise on stress in people who regularly exercise. Specifically, she is interested in the type of exercise as well as the time of day that the individual exercises. She recruits participants from a local health club who regularly participate in one of three types of exercise: swimming, aerobics, and tennis. She further divides these participants by whether they exercise in the morning or the evening. She then administers a questionnaire to each individual assessing their self-reported stress level. (HIGHER SCORE = HIGHER STRESS). Conduct a two-way ANOVA to analyze these data. Use Tukey’s test in order to conduct any necessary post hoc analyses if there are significant main effects. You do not have to follow up on significant interactions at this time.

The steps will be the same as the ones you have been practicing in Part One of the assignment—the only difference is that you are now responsible for creating the data file as well. Remember to name and define your variables under the “Variable View,” then return to the “Data View” to enter the data.

 Morning Swimming Aerobics Tennis 10 16 12 16 9 19 21 16 18 17 21 18 14 Evening 14 13 8 12 12 17 12 14 9 10 12 15 19 14

1. SPSS output (2 pts)

2. Write a current APA-style Results section based on your analyses. All homework “Results sections” must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in Current APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. For the two-way ANOVA, be sure to include statistical statements concerning the F ratios and p values for both main effects and the interaction, and interpretation statements about all 3 of these effects. (2)

3. Is there a significant interaction effect? (2)

4. Based on your results, is there 1 type of exercise that seems more effective in reducing stress than the others? Remember that higher scores = higher stress. (2)

Part Three: Cumulative Homework

1. An investigator in child development research is studying whether parenting styles have an effect on second grade students’ behavior at school. She interviews 23 volunteer families from the same class and separates them into three groups of parenting styles: authoritarian (n = 8); authoritative (n = 8); and permissive (n = 7). Their teacher fills out a behavior inventory for each of the 23 children, and the investigator collects and scores them. The scores are contained in the table below. The scores can range from 0–20, and a higher score indicates more behavior problems. Is there a significant difference between the groups? Choose the correct test to analyze this question, set up the SPSS file, and run the analysis. Follow the directions under the table on the following page.

 Authoritarian 8, 13, 4, 15, 5, 4, 9, 12 Authoritative 8, 5, 6, 4, 2, 5, 10, 13 Permissive 10, 8, 16, 9, 8, 3, 15

a) Paste appropriate SPSS output. (4)

b) Paste appropriate SPSS graph. (4)

c) Write a current APA-style Results section based on your analyses. All homework “Results sections” must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in Current APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (4)

Submit this assignment by 11:59 p.m. (ET) on Monday of Module/Week 4.