Week 5 Independent t Test Exercises

Part I

The hypothesis being tested is: Women who are working will have a lower level of depression as compared to women who are not working. 

Using Polit2SetC SPSS dataset, which contains a number of mental health variables, determine if the above hypothesis is true.

Follow these steps when using SPSS:

1. Open Polit2SetC dataset.
2. Click Analyze then click Compare Means, then Independent Sample T-test.
3. Move the Dependent Variable (CES_D Score “cesd”) in the area labelled Test Variable.
4. Move the Independent Variable (Currently Employed “worknow”) into the area labelled Grouping Variable. The worknow variable is coded as (0= those women who do not work and 1= those women who are working).  Click on Define Groups in group 1 box type 0 and in group 2 box type 1. Click Continue.
5. Click continue and then click OK.

Assignment: Through analysis of the data and use of the questions below write one to two paragraphs summarizing your findings from this t-test.

1. How many women were employed versus not employed in the sample?
2. What is the total sample size?
3. What are the mean (SD) CES-D scores for each group?
4. Interpret the Levene’s statistic. (Hint: Is the assumption of homogeneity of variance met? Are equal variances assumed or not assumed?)
5. What is the value of the t-statistic, number of degrees of freedom and the p-value?
6. Does the data support the hypothesis? Why or why not?

Part II

Hypothesis: Women who reported depression scores in wave 1 and wave 2 of the study did not have a significant difference in their level of depression. 

Using Polit2SetC SPSS dataset, determine if the above hypothesis is true.

Follow these steps when using SPSS:

1. Open Polit2SetC dataset.
2. Click Analyze then click Compare Means, then Paired Samples T-test.
3. First click on CES-D Score (cesd) and move it into the box labelled Paired Variables (in the rectangle for Pair 1 of Variable 1 and then click on CESD Score, Wave 1 (cesdwav1) and move it into the Paired Variables box (in the rectangle next to CES-D Score, pair 1, variable 2).
4. Click continue and then click OK.

Assignment: Through analysis of the data and use of the questions below write one to two paragraphs summarizing your findings from this t-test.

1. What is the total sample size?
2. What are the mean (SD) CES-D scores at wave 1 and wave 2?
3. What is the mean difference between the two time periods?
4. What is the value of the t-statistic, number of degrees of freedom and the p-value(sig)?
5. Does the data support the hypothesis? Why or why not?

Part III

Using Polit2SetC dataset, run independent groups t-tests for three outcomes. The outcome variables are CES-D Score (cesd), SF12: Physical Health Component Score, standardized (sf12phys) and SF12: Mental Health Component Score, standardized (sf12ment).

Follow these steps when using SPSS:

1. Open Polit2SetC dataset.
2. Click Analyze then click Compare Means, then Independent Sample T-test.
3. Move the Dependent Variables (CES_D Score “cesd”, SF12: Physical Health Component Score, standardized (sf12phys), and SF12: Mental Health Component Score, standardized (sf12ment) ) in the area labelled Test Variable.
4. Move the Independent Variable (Educational Attainment “educatn”) into the area labelled Grouping Variable. The educatn variable is coded as (1= no high school credential and 2=diploma or GED).  Click on Define Groups in group 1 box type 1 and in group 2 box type 2. Click Continue.
5. Click continue and then click OK.

Assignment: Create a table to present your results, use the table 6.3 in Chapter 6 as a model.  Write one or two paragraphs explaining your results.

Week 5 ANOVA Exercises

Research Question: Is there a difference in the overall satisfaction of women based on the number of housing problems (no problems, 1 problem, 2 or more problems)?

Using Polit2SetA dataset, run an ANOVA using Overall Satisfaction, Material Well-Being (satovrl) as the dependent variable and Housing Problems (hprobgrp) (this is the last variable in the dataset) as the Independent Variable.

Follow these steps when using SPSS:

1. Open Polit2SetA dataset.
2. Click Analyze then click Compare Means, then One-way ANOVA.
3. Move the Dependent Variable (Overall Satisfaction “satovrl”) in the box labelled Dependent List by clicking the arrow button.  The dependent variable is a continuous variable.
4. Move the Independent Variable (Housing Problems “Hprobgrp”) into the box labelled Factor. The hprobgrp is a categorical variable coded as (1= no hoursing problem, 2=one housing problem, 3=two or more housing problems). 
5. Click the Options button (right side of box) and click on Descriptives and Homogeneity of Variance and then click continue.
6. Click on Post Hoc (right side of box). Click on Tukey and then click continue.
7. Click OK.

Assignment: Through analysis of the data and use of the questions below write one to two paragraphs summarizing your findings from this ANOVA.

1. What is the total sample size?
2. How many women were in each of the different hprobgrp groups?
3. What are the mean (SD) overall satisfaction scores for each group?
4. Interpret the Levene’s statistic. (Hint: Is the assumption of homogeneity of variance met? Are equal variances assumed or not assumed?)
5. What is the value of the F-statistic, number of degrees of freedom and the p-value?
6. Is there a significant difference in the overall satisfaction level of women in each of the hprobgrp groups?
7. Interpret the post hoc test. When interpreting the post hoc test indicate the mean and standard deviation for each group and indicate which group was signifantly higher or lower from the other. If there is no difference between two groups indicate that as well.