Exercise 26 photo.docxLesson 26 Exercise File 2.savQue.docx
- 1. Exercise 26 photo.docx Lesson 26 Exercise File 2.sav Question.docx Page 1 of 6 SPSS Worksheet 3: (Two-Way ANOVA) This worksheet was developed by Dr. Kurt Michael of Liberty University © 2015 Name: Instructions:Lesson 26 Exercise File 2 is located at the end of the chapter under the heading Exercises in your Green and Salkind textbook. Complete the exercise and then complete the worksheet below by filling in the blanks and answering the questions. Note: The two-way ANOVA looks at three null hypotheses at one time. H01: There is no significant difference among the amount of time fathers play with their children with no disability, a physical disability, or an intellectual disability. H02: There is no significant difference between the amount of time fathers play with their male or female children. H03: There is no significant interaction among the amount of time fathers play with their male or female children with no disability, a physical disability, or an intellectual disability. Assumptions Outliers: Create a Box and Whisker plot for each group. Hint: Go to Graph > Legacy Dialog > Boxplot and use the Cluster function. See page 184 in the Salkind and Green textbook for
- 2. more information on how to display results. Insert Graph or Table Here Fill in the blanks: Group Outliers (Item #) Are there any outliers? Male Typically Male Physical Male Mental Female Typically Female Physical Female Mental < Note: Remove any outliers from the dataset before continuing.> Assumption of Normality: Run a normality test each group. Hint: Begin by going to Data > Split File > Organize output by
- 3. groups (see lesson 15, p. 64), then run Analyze > Descriptive > Explore (see lesson 40, p. 327). Insert six Tests of Normality tables below: Insert Graph or Table Here Fill in the blanks: Should you use a Shapiro-Wilks or Kolmogorov-Smirnov test? Why? Answer: Groups Significance Is the assumption of normality met? Male Typically Male Physical Male Mental Female Typically Female Physical Female Mental
- 4. Assumption of Equal Variance: Insert Levene's Test of Equality of Error Variancesa table(s) below. Hint: Begin by going to Data > Split File > RESET > then run the Analyze. Insert Graph or Table Here Fill in the blanks: Significance Is the assumption of equal variance met? Results Insert Tests of Between-Subjects Effects table(s) below: Insert Graph or Table Here Differences among disabilities Fill in the blanks: Results for Disability: Value d.f. between Groups d.f. within Groups F-statistic
- 5. F-critical (See Appendix C in Warner) p- value Partial Eta Squared Is the F- statistic greater than F-critical? Answer: Is the p- value less than .05? Answer: Should you reject or fail to reject the null? Answer: What is the effect size small, medium, or large (See Table 5.2 in Warner, p. 208)? Answer: Should you run post hoc analysis? Answer: If so, between which groups do the differences exist? Answer: Differences between genders
- 6. Fill in the blanks: Results for Gender: Value d.f. between Groups d.f. within Groups F-statistic F-critical (See Appendix C in Warner) p- value Partial Eta Squared Is the F- statistic greater than F-critical? Answer: Is the p- value less than .05? Answer: Should you reject or fail to reject the null? Answer: What is the effect size small, medium, or large (See Table 5.2 in
- 7. Warner, p. 208)? Answer: Should you run post hoc analysis? Hint: There are only two groups (Male and Females). Answer: Interaction among groups Fill in the blanks: Results for Interaction: Value d.f. between Groups d.f. within Groups F-statistic F-critical (See Appendix C in Warner) p- value Partial Eta Squared Is the F- statistic greater than F-critical? Answer:
- 8. Is the p- value less than .05? Answer: Should you reject or fail to reject the null? Answer: What is the effect size small, medium, or large (See Table 5.2 in Warner, p. 208)? Answer: Descriptive Statistics Fill in the blanks: Groups Mean S.D. Male Typically Male Physical Male Mental Female Typically Female Physical
- 9. Female Mental 14. Suppose a hypertension trial is mounted and 18 participants are randomly assigned to one of the comparison treatments. Each participant takes the assigned medication and their systolic blood pressure (SBP) is recorded after 6 months on the assigned treatment. The data are as follows. Standard Treatment Placebo New Treatment 124 134 114 111 143 117 133 148 121 125 142 124 128 150 122
- 10. 115 160 128 Is there a difference in mean SBP among treatments? Run the Step 1. Set up hypotheses and determine level of significance H1: Means are not all equal Step 2. Select the appropriate test statistic. F=MSB/MSE. Step 3. Set up decision rule. df1=k-1=3-1=2 and df2=N-k=18-3=15. Reject H0 if F > 3.68. Step 4. Compute the test statistic. Standard Placebo New Treatment n1=6 n2=6 n3=6 1= 122.7 2= 146.2
- 11. 3= 121.0 If we pool all N=18 observations, the overall mean is = 130.0. We can now compute . SSB = 6(122.7-130.0)2 + 6(146.2-130.0)2 + 6(121.0-130.0)2 SSB = 2380.4. Next, . Standard Treatment (X – 122.7) (X – 122.7)2 124 1.3 1.69 111 -11.7 136.89 133 10.3 106.09 125 2.3 5.29 128 5.3
- 12. 28.09 115 -7.7 59.29 337.34 -1)2 = 337.34. Placebo (X – 146.2) (X – 146.2)2 134 -12.2 148.84 143 -3.2 10.24 148 1.8 3.24 142 -4.2 17.64 150 3.8 14.44 160 13.8 190.44 384.84
- 13. -2)2 = 384.84. New Treatment (X – 121.0) (X – 121.0)2 114 -7 49 117 -4 16 121 0 0 124 3 9 122 1 1 128 7 49 124 -3)2 = 124.0
- 14. = 846.18. We can now construct the ANOVA table. Source of Variation Sums of Squares SS Degrees of freedom df Mean Squares MS F Between Treatments 2380.4 2 1190.2 21.1 Error or Residual 846.2 15 56.4 Total 3226.6 17 Step 5. Conclusion. We reject H0 because 21.1 > 3.68. We have statistically in mean systolic blood pressure among treatments.
- 16. X X Do the following problems using SPSS and provide a copy of the ANOVA table for each as your answer: Sullivan pp. 162-168: 14 PLUS the following problems: 1. A manufacturer wants to know which new coffee sells the best and distributes 3 types (Blue-Label, Green-Label and Red Label) to 6 of his stores. After letting customers taste the three types, the number of pounds purchased of each type of coffee on one day are recorded for the six stores. Perform an ANOVA using SPSS to determine whether there is a significant difference in sales. Blue-Label Green-Label Red-Label 13 1 5 4 1 2 10 2 2 13 2 2 11 2 6 3 4 4 2. Three topical antibiotics are tested to see how quickly they eliminate a rash in 4 people who have a history of repeated rashes of this type. The number of days to eliminate the rash in the 4 people is given in the table below: Topical antibiotic 1 Topical antibiotic 2 Topical antibiotic 3 3 5 8 9
- 17. 1 2 5 2 6 11 5 4 Conduct a one-way ANOVA to determine whether there is a significance difference in the number of days to eliminate the rash.