t Tests and ANOVA

Part I

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

Using Polit2SetC SPSS data set, which contains a number of mental health variables, determine whether the above hypothesis is true.

Follow these steps when using SPSS:

1. Open Polit2SetC data set.

2. Click on Analyze, then click on Compare Means, then Independent Sample T-test.

3. Move the Dependent Variable (CES_D Score “cesd”) in the area labeled “Test Variable.”

4. Move the Independent Variable (Currently Employed “worknow”) into the area labeled “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.

5. Click on Continue and then click on 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. Do 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 data set, determine whether the above hypothesis is true.

Follow these steps when using SPSS:

1. Open Polit2SetC data set.

2. Click on Analyze, then click on Compare Means, then Paired Samples T-test.

3. First click on CES-D Score (cesd) and move it into the box labeled “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 on Continue and then click on 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. Do the data support the hypothesis? Why or why not?

Part III

Using Polit2SetC data set, 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 data set.

2. Click on Analyze, then click on 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 labeled “Test Variable.”

4. Move the Independent Variable (Educational Attainment [educatn]) into the area labeled “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 on Continue and then click on OK.

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