48
pages

Tutorial: Part 2

For SPSS Version 11.5© DataStep Development 20041 Transformations and recoding

revisited 5

Introduction 5

Value labels 5

SPSS Tutorial and Help 6

Using online help 6

Using the Syntax Guide 7

Using the statistics coach 8

Moving around the output window 10

Sorting Revisited: Sorting by multiple

variables 11

Utilities: variable and file information 12

Utilities > Variables 12

Utilities > File Info 13

Data Transformations 14

Computing new variables 14

Performing calculations with a variable and a function 14

Creating expressions with more than one variable 16

Conditional expressions 18

Creating subsets 20

Deeper into crosstabs 23

Crosstab Statistics 23

Crosstab cells 24

Adding layers to crosstabs 26

When to include zeros in a mean 27

Gender, geography, and exercise: the universal

variables 28

Summary 28

2 Statistical procedures 31

Introduction 31

Measuring association 31

Bivariate correlations 32

Partial correlation 35Multiple correlation (multiple regression) 36

Crosstabs 37

Measuring differences 39

T-Tests 39

ANOVA 42

One-Way ANOVA 43

Summary 471 Transformations and

recoding revisited

Introduction

In the first session, we’ll explored the SPSS interface, some elimentary data man-

agement and recodes, and some basic charting. In this second session, we’ll explore

work with more complex data transformations like combining variables and subset-

ting populations and work with some of the primary statistical functions. We’ll also

look ...

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SPSS Step-by-Step

Tutorial: Part 2

For SPSS Version 11.5

© Dat

aStep

D

evelop

men

t 2004

1

Transformations and recoding revisited5 Introduction5 Value labels5 SPSS Tutorial and Help6 Using online help6 Using the Syntax Guide7 Using the statistics coach8 Moving around the output window10 Sorting Revisited: Sorting by multiple variables11 Utilities: variable and file information12 Utilities > Variables12 Utilities > File Info13 Data Transformations14 Computing new variables14 Performing calculations with a variable and a function 14 Creating expressions with more than one variable 16 Conditional expressions18 Creating subsets20 Deeper into crosstabs23 Crosstab Statistics23 Crosstab cells24 Adding layers to crosstabs26 When to include zeros in a mean27 Gender, geography, and exercise: the universal variables28 Summary28

2

Statistical procedures31 Introduction31 Measuring association31 Bivariate correlations32 Partial correlation35

One-Way ANOVA 43

Multiple correlation (multiple regression) Crosstabs37 Measuring differences T-Tests39 ANOVA42

Summary

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39

36

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Transformations and recoding revisited

Introduction In the first session, we’ll explored the SPSS interface, some elimentary data man-agement and recodes, and some basic charting. In this second session, we’ll explore work with more complex data transformations like combining variables and subset-ting populations and work with some of the primary statistical functions. We’ll also look more closely at the online help and tutorial provided by SPSS. . But first, a small clean-up task from last week: displaying and hiding value labels.

Value labels 1.Open SPSS. 2.by selecting File > Open > Data and finding the fileOpen the data file Employee data.sav in the folder named SPSSTutorialData. 3.Data View of any data file.Make sure you’re in the 4.From the menu, select View > Value Labels. If Value Labels is checked, the value labels will be displayed for variables for which you have defined value labels. If it is not checked, the actual values will be displayed.

SPSS Step-by-Step

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SPSS Tutorial and Help

5.Select View from the menu again and make sure that Value Labels is checked. If it isn’t, click it once to select it. You can turn value labels on or off at any time during an SPSS session.

SPSS Tutorial and Help SPSS provides extensive assistance through its online help, tutorial, syntax guide, and statistics coach.

Using online help 1.From the menu, select Help > Topics. 2.In the keyword field, type: crosstabs Notice that SPSS begins matching topics as soon as you begin typing. 3.From the list below the keyword field, double-clickassumptions. 4.From the keyword list, double-clickformats. Notice that the resulting help window informs you that you can “arrange rows in ascending or descending order of the values of the row variable. What’s wrong with this statement? Hint: In the rest of the computer world, “format applies to how you display text or numbers. Arranging in ascending or descending order is calledsorting.Lesson: If a standard already exists, use it; don’t confuse people by making it up as you go along. 5.From theRelated topicslist, click once on-Related procedures.The help win-dow now displays information about modeling relationships between two or more categorical variables. 6.From theRelated topicslist, click once onModel Selection Loglinear Analy-sis Data Considerations. The help window now displays more information about this technique. 7.In the keyword field, type: chi-square 8.From the keyword list, double-clickChi-square test. 9.In the next window, clickDisplay.Notice that the help window now displays general information about the Chi-square test. In addition to the list of related topics, the window also contains aShow Melink.

SPSS Step-by-Step

SPSS Tutorial and Help

10.ClickShow Me. the formopic in auqst er eht-ihcalrio te thtotuS no SPSens w op of an Internet page. 11.ClickNext.use a chi-square test, the win-In addition to an example of how to dow also identifies the sample data file you can use to follow the example for yourself. 12.ClickNext. 13.Read the text on the right side of the screen. Here is where the tutorial explains each step. And yes, that is a typo in “you must first be weight the cases
Ignore the “be. 14.ClickNextand read the steps. 15.ClickNextand read the steps. 16.ClickNext. 17.ClickNext.SPSS now displays the sample output. 18.Close the tutorial window. 19.Close the Help window. As with most help systems, you can use links to investigate topics related to the keyword you selected. In SPSS, however, you can also open the online tutorial to get more information about using a specific procedure.

Using the Syntax Guide If you need information about SPSS syntax, you can open the online Syntax Guide. This guide explains each command and provides examples of its use. The Syntax Guide is in Adobe Acrobat format. In this format, you can search the guide for spe-cific text or use the Bookmarks pane to find a specific command. 1.select Help > Syntax Guide > Base.From the menu, 2.Look at the bottom of the window where Acrobat lists the page count. Yes, that is 1490 pages. In other words, if you want, you can print the entire Syntax Guide. 3.In the bookmarks pane, click the “+ to the left of UNIVERSALS. The topic opens to display its subtopics. 4.the left of Commands.(The Commands under Universals, thatClick the “+ to is, not the Commands further down the list.) 5.topic provides information about the basic struc-Click Syntax Diagrams. This ture of SPSS syntax.

SPSS Step-by-Step

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SPSS Tutorial and Help

6.Now click the “+ to the left of the top-level COMMANDS topic. The window opens to display the subtopics for COMMANDS. 7.Scroll down until you can see the CROSSTABS entry. 8.Click the “+ to the left of CROSSTABS. 9.Click the wordCROSSTABS.The Crosstabs page is now displayed and pro-vides information about the complete format of the Crosstabs command. 10.Close the Syntax Guide window.

Using the statistics coach One of the most useful functions in SPSS is the statistics coach, particularly when you’re just starting to work with the program. The statistics coach provides prompts at which you can select what you want to do, the kind of data you’re using, and the kind of output you want. 1.From the menu, select Help > Statistics Coach. SPSS opens the first Statistics Coach window (Figure 1).

FIGURE 1.Statistics Coach, opening window

SPSS Step-by-Step

SPSS Tutorial and Help

2.Take a moment to review the choices offered in this window. 3.ClickMore Examplesa few times and notice that different types output avail-able to you. 4.For the moment, we’ll use the default task,Summarize, describe, or present data, so clickNext. 5.this case, we want to create a summary of gender by job category. Both vari-In ables are categorical, so clickNext. 6.This time we’ll change the output from the default, so selectCharts and graphsby clicking its radio button. 7.We want a simple two-dimensional chart, so clickNext. 8.ClickNext. 9.We want a bar chart, so clickFinish. 10.SPSS now opens the correct window for creating a bar chart with the type of data we have selected. 11.Drag Employment Category to the horizontal axis. 12.Gender to the Legend Variables > Color field.Drag 13.Close the remaining help window. 14.ClickOK.The chart appears in the output window. Next, we’ll use the statistics coach for a more complicated task. 15.From the menu, select Window > Employee Data.sav - SPSS Editor to get back to the Data window. 16.From the menu select Help > Statistics Coach. 17.SelectCompare groups for significant differences. 18.ClickNext. 19.We’re using categorical data, so clickFinish.The How To window appears to guide you through the steps along with the Crosstabs window. (You might have to move them around a bit so you can see both windows. 20.Select Gender and move it to the Rows pane. 21.Select Employment Category and move it to the Columns pane. 22.ClickStatistics. 23.In the Crosstabs: Statistics window, select Chi-square. 24.ClickContinue. 25.In the How To window, clickTell Me More.SPSS now displays the Data Requirements window that applies to using Chi-square. 26.ClickNext.Surprise! There is no next topic. Ha, ha, SPSS. Very funny.

SPSS Step-by-Step

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Moving around the output window

27.ClickOK. 28.ClickBack.Oh look! There is noBack. 29.Close the Data Requirements window. 30.In the Crosstabs window, clickOK.The output is now displayed in the Output window. 31.Close any remaining Help windows.

Moving around th e output window Now that you have created some charts, crosstabs, and statistics results, it’s a good time to take a closer look at moving around the output window. 1.From the menu, select Window > Output1 - SPSS Viewer. 2.the border between the panels, hold down the mouseMove your cursor over button, and move the border to the right until you can read all the titles in the icons in the contents pane as in Figure 2. FIGURE 2.Changing pane width in the output window

hold and drag here to change the pane size in the output window

3.Notice the icons on the left arranged in outline format. 4.Click the icon named Interactive Graph. The output displays moves to the first graph you created in this session.

SPSS Step-by-Step

Sorting Revisited: Sorting by multiple variables

5.Notice the “- to the left of the Output icon. The “- indicates that a topic is fully expanded. 6.Click the “- next to Output. The “- cahnges to a “+ and all the output is now hidden. If you ever “lose output on the window, check to see if the output is hidden. 7.Click “+ next to Output to expand the items again. 8.Click the icon named “Crosstabs. 9.Holding down the left mouse button, drag “Crosstabs up above “Interactive Chart. You can use the drag function to arrange your output in any order you like. 10.Below Crosstabs, click the icon for Title. 11.Click the icon for Chi-square tests. Notice that the red arrow next to the icon corresponds to the red arrow in the actual output window. 12.Under Interactive Graph, click Bar Chart. 13.Above the actual chart, double-click the title (“Interactive Graph). 14.Select all the text and type: Distribution of job category by gender 15.Click anywhere outside the title to apply the change. 16.In the navigation pane, click Title under Interactive Graph. 17.Wait about one second, then click Title again to activate the text. 18.With the text selected, type: Distribution of job category by gender 19.PressEnteror click anywhere outside the title to apply the change. Use the title function in the navigation pane to indicate what each piece of out-put it contains. “Distribution of job category by gender is a lot more informa-tive than “Title.

Sorting Revisited: Sortin g by multiple variables SPSS provides sophisticated sorting functions. You can sort by multiple variables, and you can set the sort order for each variable. For example, you could sort in order of increasing income, decreasing birthdate, and increasing expenditures. In the following task, you’ll sort the employee data set by gender (increasing) and cur-rent salary (decreasing).

SPSS Step-by-Step

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