1. Using SPSS for Windows Part II Jie Chen Ph.D. Email: jie.chen@umb.edujie.chen@umb.edu Phone: 617 287 5241 10/6/20151

2. Table of Contents Data management – Computing new variables – To sort data – Data selection and split files – Merging files Statistical procedures – Linear regressions – Regression for aggregated data – Chi-square test for grouped data – Nonparametric tests – Testing Normality 10/6/20152

3. 3 Computing New Variables Open data sample1.sav To compute a new variable we can – Use a standard formula – Use a statistical function to compute

4. 10/6/20154 Using a Formula To compute the average income for the past three years for each person: Click Compute in the Transform menu, Enter the new variable with the name of “mean” for the target variable Mean = (ptoi92+ptoi93+ptotinc)/3 Click OK to compute the mean

5. 10/6/20155 Using a Statistical Function Click the Compute in the Transform menu Click the Reset button to clear the old formula Enter average as the target variable Locate Mean on function list and move it to the Numeric Expression area (using Up arrow ) Enter ptoi92, ptoi93 and ptotinc inside the parentheses Click OK to compute the average

6. Log transformation Click the Compute in the Transform menu Click the Reset button to clear the old formula Enter lnincome as the target variable Click on Arithmetic in Function group: text box Locate Ln on functions and Special Variables: list and move it to the Numeric Expression area (using Up arrow ) Enter ptotinc inside the parentheses Click OK to compute log of ptotinc.

7. 10/6/20157 Sorting Data Sorting data involves reordering of data using values of one or more variables. Sorting data on one variable Sorting data on more than one variables

8. 10/6/20158 Sorting Data on One Variable Click Data/Sort Cases in the Data Editor Window Click age and move it to the “Sort by:” text box Click Ascending radio button Click OK

9. 10/6/20159 Data Sorted by Age

10. 10/6/201510 Sorting Data on Two Variables Click Data/Sort Cases Click age and move it to the “Sort by:” text box Click educ and move it to the “Sort by:” text box Click Ascending radio button Click OK

11. 10/6/201511 Data Sorted by Two Variables

12. 10/6/201512 Three Ways of Data Selection If condition is satisfied : to select data that meet if conditions Random sample of cases:randomly chose a specified percentage of cases Based on time or case range: to select data from a specified range

13. 10/6/201513 If Condition Is Satisfied To choose data that meet If conditions: Click the Select Cases in the Data menu Click the If condition is satisfied radio button Click If push button to open the Select Cases: If dialog box

14. 10/6/201514 The If condition If we are interested in the personal total income for females, we need to select the only observations whose sex is female. Type in sex = 1 in the Select Cases: If dialog box, (1 = “female”) Click Continue to confirm the rule

15. 10/6/201515 Two Choices for Unselected Cases If one clicks the Filtered radio button, the unselected cases remain in the Data Editor, but are not used in analyses. If one clicks the Deleted radio button the unselected cases are deleted from the Data Editor Window.

16. 10/6/201516 Complex If conditions Suppose we want to select cases meeting two conditions: region = 1 and age >= 30 Type in “region = 1 & age>=30” in the Select Cases: If window Click Continue to confirm the rule

17. 10/6/201517 The Case Deletion Choice Switch to the Data Editor Window Click the Select Cases in the Data menu Click the Deleted radio button in the Unselected Cases Are: area Click the OK to delete unselected cases from Data Editor Window

18. 10/6/201518 The Data Editor Window Containing Only Selected Observations

19. 10/6/201519 Split File The data file is split into separate groups for analysis based on the values of a grouping variable The same analysis is applied to separate subgroups simultaneously The results for all the subgroups will be presented together

20. 10/6/201520 To Split a Data file Open sample2.por Click the Split File in the Data menu Click the Organize output by groups radio button Move sex to the the Groups Based on list box Click the OK push button to Split File

21. 10/6/201521 Descriptive Statistics Based on Split File Click Statistics/Summarize/descriptive Click age in variable list box Click OK

22. 10/6/201522 Presenting results by selecting Compare groups

23. 10/6/201523 Turn Off the Split File Processing Select Split File in the Data menu Click Analyze all cases in the Split File dialog box click OK to set analyses to all cases (turn off split file)

24. 10/6/201524 Merging Files Data can be combined in two ways Merging different cases according to the same variables (adding observations) Merging different variables according to the same cases (adding variables)

25. 10/6/201525 Merging Cases In the Data Editor Window Open a data file row1.sav Click Data/Merge Files/Add Cases, the dialog box of Add cases: Read File is open as shown in the note page Select file row2.sav and Click open, then the dialog box of Add Cases from... is open Click OK, the observation from row2.sav are placed in Data Editor Window after row1.sav

26. 10/6/201526 The Add cases from … dialog box

27. 10/6/201527 Merging Variables Open file col1.sav Click Data/Merge Files/Add Variables. The dialog box Add Variable: Read File shown in the note page will be displayed. Select file col2.save and Click open. Then the dialog box of Add Variable from... Will appear Click OK.

28. 10/6/201528 The Add Variable from … dialog box

29. 10/6/201529 The Merged File

30. 10/6/201530 Introduction to Regression Simple Regression Multiple Regression Regression Plots Regression for aggregated data

31. 10/6/201531 Simple Regression Click Analyze/Regression/Linear then the Linear Regression dialog box is open Use ptotinc (personal total income) as the dependent variable Use educ as the independent variable Click OK

32. 10/6/201532 The Dialog Box of Linear Regression

33. 10/6/201533 The Output for the Regression

34. 10/6/201534 The Estimated Regression Equation

35. 10/6/201535 The Fitted Line

36. 10/6/201536 Examing the Residual Click Dialog Recall Tool Click Linear Regression Click plots… in the Linear Regression dialog box In the Linear Regression: Plots dialog box, chose ZRESID as the Y and ZPRED as the X variables. Click Histogram Click Continue Click Ok

37. 10/6/201537 The Scatterplot of Residuals

38. 10/6/201538 Multiple Regression

39. 10/6/201539 Running a Multiple Regression

40. 10/6/201540 The Output of Multiple Regression

41. 10/6/201541 The Fitted Model Y = -13301+ 2672 X1-13106 X2 + 145 X3

42. 10/6/201542 Residual Plots Click Plots in Linear Regression Dialog Box Put ZRESID as the Y variable and ZPRED as the X variable in a scatterplot Chose Histogram and Normal probability plot in the Standardized Residual Plots

43. 10/6/201543 Histogram

44. 10/6/201544 Normal Probability plot

45. 10/6/201545 To aggregate data Using Current Population Survey 2006 (CPS2006) data Click on Data/Aggregate Data – Break Variable(s): – Summaries of Variable(s): Mean, Median, and Sum First, Last, Minimum, and Maximum values – To save aggregated variables

46. 10/6/201546 A random sample from Current Population Survey (CPS2006)

47. 10/6/201547 The mean and median wages by years of education

48. 10/6/201548 A regression line of average income

49. 10/6/201549 A regression line of median income

50. 10/6/201550 An Example taken from 1982 General Social Survey

51. 10/6/201551

52. 10/6/201552 Death Penalty Data in SPSS

53. 10/6/201553 Crosstabulation with Row Percentage

54. 10/6/201554 Comparison of Row Percentages

55. 10/6/201555 Repeated Measures Analysis Repeated measures analysis of variance involves testing for significant differences in mean when the observation appears in multiple levels of a factor.

56. 10/6/201556 Opening the data Click File/Open in the Data Editor Window Click SPSS (*.sav) choice on the File of type pull-down list Look in Floppy (A) and click blood in the file list Click Open

57. 10/6/201557 Opening the Repeated Measures Dialog Box Click Analyze/General Linear Model/Repeated Measures Replace factor1 with time in the Within- Subject Factor Name text box Press Tab key to move to the number of levels text box and type 3 Click Add push-button and then click Define push-button

58. 10/6/201558 Click and drag from time1 to time3 Click right arrow to move time1 to time3 into the Within-Subject Variables box Click gender and move it to the Between- Subjects Factor box Click OK push button

59. 10/6/201559 Examining the results

60. 10/6/201560 Compare the Main Effects Click Dialog Recall Tool Click Define Push-button Click Options push-button Move time into the Display Means for list box Click Compare Main Effects checkbox Click Continue to process the request Click Ok

61. 10/6/201561 Pairwise Comparisons

62. Testing the Normality To test if Age variable is normal distributed. Using file: sam1000.sav Using both graphs and tests Click on Analyze/Descriptive Statistics/Explore… – To chose Age variable in the dependent list – Click on Plots push button. – Check Normality plots with tests. 10/6/201562