Intermediate Workshop SPSS

1. Intermediate WorkshopSPSS CSU Fresno March 15, 2010

2. Agenda for the Intermediate SPSS Workshop • Cross tabulations • Bivariate • Multivariate • Comparing means • Independent sample t test • Paired-sample t test • One-way analysis of variance • Regression and correlation • Bivariate • Multivariate • Graphs

3. Opening the Data Files (.sav) for this Workshop • The data files we’re going to use in this workshop are .sav files. • One of the data sets that we’re going to use comes with the text – gss06a.sav. You can download it from the website that has the text: http://www.ssric.org/tr/onlinetextbooks. Look for the text that says “Right click here to download GSS06A.”

4. Opening the Data Files (.sav) for this Workshop • We’re also going to use the “states” data set, a file with information about each of the 50 states. • You can download the data from http://www.csupomona.edu/~jlkorey/POWERMUTT/Data • You can also download a codebook describing it from http://www.csupomona.edu/~jlkorey/POWERMUTT/Codebooks/states.html.

5. Choosing options within SPSS • Click on “Edit” and “Options.” • Under “Variable Lists,” check “Display Names” and “Alphabetical.” • Under “Output Labels,” select “Names and Labels” in the first box, and “Values and Labels” in the second.

6. Cross Tabulations(see chs. 5 and 8 in text) • Click on Analyze > Descriptive Statistics > Crosstabs. • Select PRES04 as the row variable, and SEX and MARITAL as column variables. • Click on Cells and check Column. • Click on Statistics and check Chi Square and Cramer’s V. • Click on OK.

7. Cross Tabulations(with a control variable) • Click on Analyze > Descriptive Statistics > Crosstabs • Move SEX from second to third dialog box. • Click on OK.

8. Copying the Table • Select the table by single clicking on it. • Click on Edit and then on Copy. • Go to your report in Word and click on Edit > Paste Special > JPEG > OK.

9. Exercises for Crosstabs • Using the gss06a.sav data, crosstabulate actual income (INC06REC) and perceived income (FINRELA), treating the later as your dependent variable. Use Kendall’s tauc to measure association. • Use crosstabs to test a hypothesis of your choosing.

10. Ways to Compare Means(see ch. 6 in text) • Independent-sample t test • Paired-sample t test • One-way analysis of variance

11. Computing Means • Click on Analyze/Compare Means and then on Means. • Move AGEKDBRN into the “Dependent List”. • Move SEX into the “Independent List” • Click on OK.

12. Computing Means (continued) • Requesting other statistics – click on “Options” and select the other statistics you would like. • Further breakdowns – Click on “Next” and select a further breakdown. • Move DEGREE into the “Layer 2” box and click on “OK.” • Now move DEGREE into the “Layer 1” box and SEX into the “Layer 2” box.

13. Exercises for Comparing Means • Compute the mean age (AGE) of respondents who voted for Bush, Kerry, and someone else (PRES04). Which group had the youngest mean age and which had the oldest mean age? • Compute the mean number of hours that people with different levels of education (DEGREE) watch television (TVHOURS). Who watches more television – those with less education or those with more education?

14. Independent Sample T Test • Independent samples are samples where the composition of one sample does not influence the composition of the other sample. • Click on Analyze/Compare Means/Independent Sample T Test. • Select the variable that defines the two groups. This is called the “Grouping Variable”. Let’s use SEX as our grouping variable. • Click on “Define Groups” and indicate the values that define the two groups. Males are coded 1 and females are coded 2. • Click on continue.

15. Independent Sample T Test • Select the “Test Variable”. This is the variable that you want to use to compare the two groups. Let’s use AGEKDBRN as our test variable. • Click on “OK.”

16. Exercises for Independent Sample T Test • Use the independent sample t test to compare the mean age (AGE) of respondents who believe and do not believe in life after death (POSTLIFE). Which group had the highest mean age? Was the difference statistically significant at the .05 level of significance? • Compare the mean family income (INCOME06) of men and women (SEX). Who had the higher income? Was it statistically significant at the .05 level of significance?

17. Paired Samples T Test • Paired samples are samples where the composition of one sample determines the composition of the other sample (e.g., sample of husbands and wives married to each other). • Click on Analyze/Compare Means/Paired Samples T Test.

18. Paired Samples T Test (continued) • Select your paired variables by clicking on the first variable in the list on the left and then clicking on the arrow. Then click on the second variable and click on the arrow again. They should now be in the “Paired Variables” box on the right. Let’s use MAEDUC and PAEDUC as our paired variables. • Move these two paired variables to the “Paired Variables” box. • Click on “OK.”

19. Exercises for Paired Sample T Test • Use the paired-sample t test to compare mother’s socioeconomic status (MASEI) and father’s socioeconomic status (PASEI). Who has the highest mean socioeconomic status – mothers or fathers? Was the difference statistically significant? • Compare the mean years of school completed for respondents (EDUC) and their spouses (SPEDUC). Who has the higher years of school completed? Was the difference statistically significant?

20. One-Way Analysis of Variance • Now we want to compare means for more than two groups. • Click on Analyze/Compare Means/Means. • Select the variable that defines your groups by clicking on it and moving it to the “Independent List” box. Do this for DEGREE. • Select the variable that you want to use as your comparison variable and move it to the “Dependent List” box. Let’s use AGEKDBRN as our comparison variable.

21. One-Way Analysis of Variance (continued) • Click on “Options” to open the “Means: Options” box. • Click in the “Anova table and eta” box to select it and indicate that you want to do a One-Way ANOVA. • Click on “Continue” and on “OK.”

22. Exercises for One-Way ANOVA • Use One-Way ANOVA to compare the mean years of school completed (EDUC) of respondents who voted for Bush, Kerry, and someone else (PRES04). Which group had the most education and which had the least education? Was the F-value statistically significant? • Compare the number of hours watching television (TVHOURS) for people of different levels of education (DEGREE). Who watches more television – those with more education or those with less education? Was the F-value statistically significant?

23. Dummy Variables • Open the STATES.SAV file. • Create new variable for whether state is in South. • Click on Transform • Click on Compute Variable • Under Target Variable, type SOUTH. • Under Numeric Expression, type 0. • Click on OK.

24. Dummy Variables (continued) • Click on Transform • Click on Compute Variable • Under Numeric Expression, type 1. • Click on If • Click on Include if case satisfies condition. • In 1st box, type REGION = 3. • Click on Continue and OK. • When asked if you want to Change exiting variable?, click on OK.

25. Dummy variables (continued) Create new variable called WEST that is 1 if REGION equals 4, 0 otherwise. Note: be sure to click on Reset in the Compute Variable dialog box before proceeding further.

26. Correlation and Regression(see chs. 7 and 8 in text) • Click on Analyze > Correlate > Bivariate. • Select PID, IDEO, MARRIED, and SOUTH and WEST • Click on one-tailed and on OK.

27. Correlation and Regression(continued) • Click on Analyze > Regression > Linear. • Select PID, as the dependent variable, and IDEO, MARRIED, SOUTH and WEST as independent variables. • Click on OK.

28. Exercises for Correlation and Regression • Open the GSS06A file. Create a correlation matrix among the following: EDUC, MAEDUC, PAEDUC, PRESTG80, and SEI. • Open the STATES file. What explains variation among states in propensity toward charitable giving (CHARITY)?

29. Charts/Graphs(see ch. 9 in text) • Pie charts • Bar charts • Histograms • Boxplots • Scatterplots

30. General Information About Graphs • There are three ways to produce charts in SPSS • Chart Builder • Legacy • “Classical” • Interactive • We’ll be using the last of these

31. Simple Pie Charts Switch to the GSS06A data set. Select Graphs > Legacy Dialogs > Interactive> Pie > Simple. Move DEGREE into first box on right. Move $PCT into second box on right. Click on OK.

32. Editing the Pie Chart • Double click anywhere inside the pie chart to open the Chart Editor. • Click Options > Title, and add a title to your chart. • Click Elements > Show Data Labels to display percents and data labels. • Click on the slice you want to explode. Now click Elements > Explode Slice.

33. Copying the Pie Chart • Close the Chart Editor • Select the pie chart by single clicking on it. • Click on Edit and then on Copy. • Go to your report in Word and click on Edit > Paste Special > JPEG > OK.

34. Simple Bar Charts Select Graphs > Legacy Dialogs >Interactive> Bar Move $PCT into first box on right. Move DEGREE into second box on right. Click on OK.

35. Clustered Bar Chart • Select Graphs > Legacy Dialogs >Interactive> Bar • Move $PCT into first box on right. • Move DEGREE into second box on right. • Move SEX into third box on right. • Click on OK.

36. Histogram • Select Graphs > Legacy Dialogs >Interactive> Histogram • Move $PCT into first box on right. • Move AGE into second box on right. • In Histogram tab, check box for Normal curve. • Click on OK.

37. Boxplot for Single Variables • Open the STATES.SAV file. • Select Graphs > Legacy Dialogs >Interactive> Boxplot • Move MEDIANHS into first box on right. • Move STATE into last box on right. • Click on OK.

38. Boxplot by Categories of a Second Variable • Select Graphs > Legacy Dialogs >Interactive> Boxplot • Move MEDIANHS into first box on right. • Move REGION into second box on right. • Move STATE into last box on right. • Click on OK.

39. Scatterplots • Select Graphs > Legacy Dialogs > Interactive> Scatterplot. • In Assign Variables tab: • move PID into 1st box. • move IDEO into 2nd box. • move REGION into 4th box. • move STATE into last box • Click on OK.

40. Scatterplots (continued) • In Fit tab: • Under Method, select Regression. • Click on OK.

41. Exercises for Graphs • Using GSS06A.SAV: • Create a pie chart and a bar chart for POLVIEWS. • Create a histogram for SEI. • Create a boxplot for SEI and then create separate boxplots for males and females. • Using STATES.SAV, create a scatterplot for TRAFFIC and ENERGY. • Try various ways of editing your graphs. • Copy the graphs into Word.

42. Where do you go from here? • Explore the help menu. • Spend some time playing with SPSS. • Try out different ways of analyzing your data. • Show them to others for suggestions.