User Note

SPSS 6 for Windows

System: MS-Windows

Number: UN 524/2

Author: James Currall

Date: March 1996

Summary: SPSS stands for the Statistical Package for the Social Sciences. SPSS for Windows is a version of this statistical package that is especially configured to work in the Windows operating environment. This document describes how to use SPSS in the Windows environment. It assumes that you have some familiarity with Windows and the statistical procedures available in SPSS.

Contents

SPSS was originally designed for use by social scientists to analyse data from surveys. Over the years it has grown to include a wide range of techniques, which are outlined briefly below. SPSS for Windows is a version of this statistical package that is especially configured to work in the Windows operating environment. This version has a wide range of statistical procedures and also a selection of high-resolution graphics facilities. It also has links to many other packages.

The basic facilities of SPSS for Windows are similar to those in SPSS as used on the central Unix computer systems. The MS-Windows version surrounds this core with an extensive help and menu system.

The limit on the size of problem that can be tackled is essentially dependent on the amount of RAM or virtual memory available on your machine. There are effectively no limits on the number of variables or cases that the program can handle.

The basic MS-Windows version is supplied with a number of additional options (meaning that their installation is optional - they are all provided with the package under the University's licence). The options are listed below:

Professional Statistics

contains statistical procedures for classification and clustering, discriminant analysis and factor analysis.

Advanced Statistics

contains procedures for logistic regression, loglinear analysis, multivariate analysis of variance and survival analysis.

Tables

provides sophisticated ways of constructing and arranging cross-tabulations.

Trends

provides procedures for the analysis of time series data.

Categories

provides procedures for the analysis of nominal, ordinal and mixed categorical data by correspondence analysis and allied techniques.

High-resolution graphics are built into the base package, so there is no need to link to other graphics packages as is the case with some other versions of SPSS.

Links to other packages are provided by Open DataBase Connectivity (ODBC), Object Linking and Embedding (OLE) and Dynamic Data Exchange (DDE). In addition SPSS for Windows can read and write files from Excel, Multiplan, Lotus 123, Lotus Symphony and dBase. It can also access Oracle and SQL Server database files.

The way in which you start SPSS depends on how it was installed. This information should be provided by the person who installed SPSS on the computer.

If SPSS has been installed using the default settings, it will be located in a Windows group called SPSS for Windows. SPSS is then started by clicking on the SPSS icon in this group.

On machines in the centrally provided clusters and teaching laboratories run by the Computing Service, the default settings are not used because the package is installed on a local area network rather than on stand-alone machines. On these machines SPSS is started by clicking on the SPSS icon in the Data Handling Packages program group.

The SPSS windows environment is very similar to that found in other MS-Windows applications. The main features are outlined below.

SPSS for Windows has a number of window types.

Application window

This is the main window into which the others fit. It provides you with the usual pull-down menus which give access to the statistical and graphical facilities of SPSS and allow you to control the MS-Windows environment.

Output window

This is an editable text window where the results of analyses are written.

Data Editor

This is a spreadsheet-like data editor, where you can define variables and input and edit data.

Chart Carousel

The charts and graphs produced by SPSS are accessed through this window, which opens the first time you create a chart or graph. If you produce multiple charts you can view them through the chart carousel before modifying, saving or discarding them.

Chart window

Each chart can be edited in its own window, to change fonts, colours, symbols etc.

Syntax window

This is an optional window where SPSS instructions can be prepared in the form of commands similar to those used in other versions of SPSS. There are some facilities which are only available through the Syntax window, and some options to other commands that cannot be accessed through the menu system.

Help window

Help is available through the standard MS-Windows help system which brings up a window of its own.

Glossary window

If SPSS uses a term in its output which you do not understand, you can look it up in its on-line glossary as it has a built in glossary of statistical terms.

When SPSS starts up, it provides an Application window together with an Output window and a Data Editor window.

Like most MS-Windows applications, the SPSS Application window has a row of pull down menus along the top of the screen:

Data, Output and Syntax Window Menus

File

Gives access to data files, spreadsheet files, text files and printing.

Edit

Allows you to modify text in the Output or Syntax windows, and to cut, copy and paste items to and from the Clipboard.

Data

Lets you make global changes to data, merge files, transpose variables and cases and create subsets of data for analysis.

Transform

Makes changes to selected variables and computes new variables from existing ones.

Statistics

Gives access to the extensive selection of statistical procedures that SPSS can perform.

Graphs

Allows you to create many different types of charts and graphs (some graphs are also created by statistical procedures).

Utilities

Allows you to change fonts, access DDE, display information about SPSS files, and gain access to an index of SPSS commands and their syntax.

Window

Allows you to arrange, select and control the attributes of the various SPSS windows.

Help

Opens the SPSS help system which contains a great deal of information on SPSS and its many features. Help is also available from the dialog boxes associated with particular statistical and graphical procedures.

Chart Window Menus

File

Allows saving and exporting of charts, applying chart specifications via templates and printing.

Edit

Allows you to cut, copy and paste charts to and from the Clipboard.

Gallery

Allows you to select from a range chart types compatable with the data in your current chart. The new chart type can replace or supplement your existing chart.

Chart

Gives access to a range of layout, annotation, titling and footnote facilities.

Series

From this menu you can select data series and categories to display or omit.

Attributes

From the attributes menu, you can open a set of palettes which can be used to select fill patterns, colours, marker types and sizes and line styles and widths.

Window

Allows you to arrange, select and control the attributes of the various SPSS windows.

Help

Opens the SPSS help system which contains a great deal of information on SPSS and its many features. Help is also available from the dialog boxes associated with particular statistical and graphical procedures.

The toolbar provides quick access to many frequently used features of SPSS. This is a new feature in SPSS version 6.1.

The Core Tools

Open File

Displays a dialog box for selecting and opening files.

Save File

Saves the file in the active window. For new documents, displays a dialog box for saving files.

Print File

Displays the print dialog box for the type of document that is in the active window.

Recall Dialog

Displays a list of recently opened dialog boxes. To display one of the dialog boxes on the list, click on its name.

Cycle Output

Activates the next output window in the stack of windows.

Cycle Syntax

Activates the next syntax window in the stack of windows.

Cycle Chart

Activates the next chart window in the stack of windows, including the Chart Carousel. It does not cycle through the charts within the Carousel.

Go to Chart

When an output window is active, this tool activates the chart that corresponds to the next high-resolution chart line in the output window.

Go to Data

Activates the Data Editor. When a point is selected on a chart that is still linked to the data, clicking on this tool activates the Data Editor and displays the high-lighted case associated with the selected points.

Go to Case

Displays the Go to Case dialog box. You can use it to scroll to a case in the Data Editor.

Variable Info

Displays the Variables dialog box. In the variables dialog box, you can see the variable label, variable type, missing values and value labels for any selected variable.

Data, Output and Syntax Window Tools

Text Search

Displays the Search for Text dialog box, which you can use to search for text strings in an output or syntax window.

Syntax Help

If an SPSS command is selected, this tools displays the associated syntax chart. If no command is selected, an index of SPSS commands is displayed.

Glossary

Displays a definition of a selected term in an output window. If no text is selected, or if no glossary entry matches the selected term, a Help search index of glossary entries is displayed. Each glossary entry describes a term found in SPSS output. The glossary is displayed in a Help window.

Designate Window

If a syntax window is active, this tool designates the window as the one to receive syntax when you click on Paste in dialog boxes. If an output window is active, it designates the window as the one to receive output when you execute an SPSS procedure. In either case it puts an exclamation mark at the beginning of the window's title.

Run Syntax

Submits the highlighted commands in a syntax window to the SPSS processor, or if none are selected, runs from the current insertion point.

Pause/Scroll

Permits pausing of the output, so that you may review it as it is produced rather than waiting until the currently executing procedure has finished. Click on it again to restart the scrolling of output.

Page Up

Scrolls an output window one page up.

Page Down

Scrolls an output window one page down.

Block Up

In an output window, clicking on this button scrolls to the previous block of output. Each SPSS procedure that you run creates an output block. The start of each output block is marked with a special symbol.

Block Down

In an output window, clicking on this button scrolls to the next block of output.

Data Search

Opens the Search for Data dialog box, which you can use to search for a data value in the selected variable in the Data Editor.

Insert Case

In the Data Editor, clicking on this tool inserts a case above the case containing the active cell.

Insert Variable

In the Data Editor, clicking on this tool inserts a variable to the left of the variable containing the active cell.

Value Labels

Switches between actual values and value labels in the Data Editor.

Use Sets

Opens the Use Sets dialog box. You can select the sets of variables to be displayed in the dialog boxes.

Chart Carousel Window Tools

The Chart Carousel window icon bar has the following buttons:

Edit

Allows editing of the current graph, by transferring it to a Chart window.

Discard

Discards the current graph from the Chart Carousel.

Up Arrow

Displays the previous graph in the Chart Carousel.

Down Arrow

Displays the next graph in the Chart Carousel.

Chart Window Tools

Select Points

Switches between point selection mode and chart edit mode.

Fill Type

Allows you to select the fill pattern for solid objects on a chart.

Colour

Allows you to change the colours of objects on a chart.

Marker

Allows you to change the markers used and their size on a chart.

Line Style

Allows you to change the style and width of lines on a chart.

Bar Style

Opens the Bar Styles palette, which allows you to add a drop shadow or a 3-D effect to a bar.

Bar Labels

Opens the Bar Label Styles palette, which allows you to label each bar on a bar chart with its numerical value.

Interpolation

Opens the Line Interpolation palette, which allows you to connect the data points on a line chart or scatterplot.

Text Attributes

Allows you to change the font and text size of element on a chart.

3-D Rotation

Opens the 3-D Rotation dialog box, which allows you to rotate a 3-D scatterplot.

Swap Axes

Swaps the axes on a 2-D chart, which changes the orientation between vertical and horizontal.

Explode Pie

Separates one or more slices from a pie chart for emphasis.

Line Breaks

Allows you to control whether line charts have a break where missing values should be.

Options

Opens the Options dialog box for the type of chart that is in the active window.

Spin Mode

When a 3-D scatterplot is in the active window, this tool changes the chart to spin mode, where the chart is displayed with only the tripod and points.

At the bottom of the SPSS Application window, there is a status bar giving information about the current state of the following:

Command Status

Tells you how many cases have been processed so far during the execution of a procedure.

Filter Status

If you are working with a random sample or subset of cases, this reminds you that you are not working with all the data.

Weight Status

Indicates that a weight variable is currently being used to weight cases for analysis.

Split File Status

Indicates when split file processing is currently being used to process groups of cases separately.

Help is available either via the standard Windows help menu or from the Help button in each of the dialog boxes which SPSS uses to get information on how you wish to carry out the statistical and graphical procedures.

SPSS provides a glossary of the statistical terms that occur in its output. If you access Glossary directly from the Help menu, as you type the term to be looked up, the first match for the characters that you have typed so far is displayed. The definition given will change as you add more letters until either the word you want is displayed or the Glossary stops at a similar word, which means that the term that you want is not in the Glossary. If you select Glossary directly from the Output window, you can highlight a word, copy it to the Clipboard and paste it into the Glossary search box and thus look it up in the Glossary without having to retype it.

If you want to copy the definition from the Glossary, pasting it into your current window, use the Edit menu in the Glossary to copy the definition, or part of it, to the Clipboard and then use the usual Windows paste facilities from the main Edit menu.

To look up an item:

1. Select the Glossary item from either the Help menu or the Glossary button in the Output window.
2. Highlight or type the term you want more information about.

SPSS for Windows will read and write a range of different file types. Some of these are specific to SPSS whilst others are the input or output files of other packages and thus enable data and output to be transferred between packages.

SPSS for Windows will read and write the following types of data file:

.SAV

SPSS for Windows system files

.SYS

SPSS/pc+ system files

.POR

SPSS portable files

.XLS

Excel spreadsheet files

.WK*

Lotus 123 spreadsheet files

.WR*

Lotus Symphony files

.SLK

Microsoft Symbolic Link format files

.DBF

dBase II, III and IV database files

.DAT

Tab-delimited or ASCII data files

SPSS for Windows also reads and writes the following other types of file:

.SPS

SPSS command files

.INC

SPSS command files for use in batch mode

.LST

SPSS output files

.CHT

SPSS chart files

You will often want to give SPSS the name of a file, such as a file containing your data or one to store the results of your analysis. To do this you select an appropriate item from the File menu. Reading and writing all file types brings up the same dialog box. This is a standard Windows files dialog with the following items requiring selection:

1. Select the correct disk drive, e.g. C:
2. Select the correct directory on the drive, e.g. SPSS.
3. Select the correct file type from the list available. In most cases SPSS will suggest the correct type.
4. Select the required file from the list or type the name for the file.

SPSS can read and write data from the following packages:

• Excel
• Multiplan
• Lotus 123
• Lotus Symphony
• dBase

There are four ways of giving SPSS commands:

• Use the pull-down menus to specify what you want SPSS to do, and fill in the appropriate dialog box and sub-dialog boxes. Sub-dialog boxes give extra information to SPSS that cannot be fitted into the main dialog box for the command. Sub-dialog boxes are closed when completed by clicking on the Continue button. The main dialog boxes are closed and the instructions given to SPSS by clicking on the OK button.
• Construct commands from experience without using the SPSS menus. Commands are written into an optional Syntax window. You can obtain a syntax window by clicking on the File menu, the New sub-menu and the Syntax item. The Syntax window has a RUN button for submitting the SPSS commands to the command processor.
• Execute commands from a file prepared outside SPSS. This approach is useful for frequently used sets of complicated commands. The commands are loaded into a Syntax window via the File menu and Open sub-menu and run from there.
• In the Windows File Manager double click on an SPSS command file with the .INC filename extension. This will execute the commands in a sort of batch mode, producing an output file with the same file name as the command file but with .LIS extension.

Data definition may be carried out with command syntax as in earlier versions of SPSS but advantage may be taken of the Windows user interface which simplifies the task. The following set of steps describe the process.

1. Double click on the label var at the top of the first column in the Data Editor window. This will open up a dialog box for defining a variable.
2. Type the name of the variable in the appropriate box.
3. Click on the Type button and set the variable type to something appropriate, the width to an appropriate setting and the number of decimal places to the number required. When you have completed this click on the Continue button, to close the Type sub-dialog.
4. Click on the Missing Values button and select Discrete missing values. Fill in the first Discrete missing value box with the value used to code Missing for the variable, and then click on the Continue button.
5. Click on the Labels button. Fill in the Variable Label box with a suitable description of the variable. If the variable is categorical you may also wish to define Value Labels, if not skip the next step.
6. If you need to supply Value Labels as well as Variable Labels, fill in a numeric value and a text value label for each category of the variable. For example if the values were (1 male, 2 female), place a 1 in the Value box and male in the Label box then click on the Add button. Repeat this procedure for 2 and female. When you have finished defining labels for your variable click on Continue.
7. When you have finished with labels, click on the OK button to complete the variable definition and close the Variable Definition dialog.

The above steps may be repeated as often as necessary to define all your variables.

8. After defining the variables you can enter the actual data into the Data Editor window, by typing the numbers in the cells. The columns are the variables that you have defined and the rows are the cases.
9. Finally you should save the data in an SPSS system file. Select the File menu and then Save As .... In the standard Windows files dialog, select an appropriate directory on a suitable drive and type the filename into the file name box.

SPSS for Windows incorporates a range of high-resolution graphics facilities. The graphs are easily created and may be incorporated into reports and other documents. They may also be printed using the standard range of Windows printer and plotter drivers.

The following types are available:

• Bar, Line, Area and Pie Charts
• High and Low Charts
• Boxplots and Error Bar Charts
• Scatterplots and Histograms
• Pareto and Control Charts
• Normal Probability Plots
• Sequence Charts

The procedures to produce charts are available from the Graphs menu. Once you have selected the graph type, you will be presented with a set of dialog boxes to specify the graph or chart required.

When charts are created they are placed in the Chart Carousel until you dispose of them. If you do not require to edit the chart, you can print, save or incorporate the chart into a document directly from the Carousel. If however you wish to edit the chart, you need to transfer it to a Chart window. This is done by clicking on the Edit button on the Chart Carousel icon bar. The other buttons on the icon bar allow you to cycle through the charts in the Carousel, discard the currently displayed chart or return to the SPSS Output window.

When you have transferred a chart to a Chart window, it may be edited. Clicking on any element of the chart allows changes to be made to its colour, size etc. Double clicking on an element allows more fundamental aspects to be changed, such as the text of a label or the drawing of tick marks or grid lines. Chart windows have icons along their top edge which allow a variety of modifications to be made easily.

The first thing to do when printing a graph is to select the correct printer driver. This is done via the File menu and Printer Setup item. The dialog box used is the standard Windows printer selection box which allows the printer, paper size and graph orientation to be selected.

To print a graph, select the File menu and the Print item. The dialog boxes allow some selection of the graphs to be printed and which fill patterns and line styles are to be used. Clicking on the OK button sends the graph to the printer.

There are two ways to do this, but the only difference is in the final step:

1. Make the Chart window active or select the correct graph from the Chart Carousel.
2. Select the Edit menu and the Copy Chart item. This makes a copy of the graph on the Clipboard.
3. Switch to your document in the word processing program.
4. Select the Edit menu and the Paste Special item.
5. Finally, choose one of these two options:

• To Copy and Paste the graph, select Picture in the dialog box and click on Paste. This pastes the chart into your document. Since the pasted graph is not linked, subsequent changes to the graph in SPSS will not change the graph in the document.
• To use OLE, select Picture in the dialog box and click on Paste Link. This pastes the chart into your document. Since the pasted graph is linked, subsequent changes to the graph in SPSS will also change the graph in the document.

All the standard Windows methods for linking packages together are provided in some form in SPSS for Windows.

DDE

Dynamic Data Exchange allows package to request data from each other or give each other instructions. The SPSS implementation of DDE is for Server mode only. This means that SPSS offers its data to other applications but will not access data belonging to the other applications. This mode allows results from an SPSS analysis to be included in a report, without leaving the report. The application in which you are writing the report opens SPSS, gives it instructions and receives the report directly from SPSS.

OLE

The main use of Object Linking and Embedding in connection with SPSS it to construct a chart or graph in SPSS and link it to a report in a word processing program. With OLE there is no need to store a copy of the chart in the word processed document. The chart is inserted into the document when required for display or printing directly from SPSS.

ODBC

An increasing number of data based applications running under Windows are supporting the Open Data Base Connectivity standard which enables them to share data. SPSS supports this standard.

SQL

Structured Query Language server databases can be opened directly from within SPSS, which provides the SQL environment from which to make the request for the appropriate subset of the data. In this form of access SPSS selects data from the database rather than reading the whole database or file.

Oracle

Oracle databases can be open directly from within SPSS, which provides the Oracle query environment from which to make the request for the appropriate subset of the data. In this form of access SPSS selects data from the database rather than reading the whole database or file.

Details of the large number of manuals available for SPSS are given below. All titles are published by Prentice-Hall. If you have any queries about using SPSS that can not be answered by reading any of this documentation, please contact the Computing Service Help Desk (phone 4831 or send electronic mail to adviser@compserv.gla.ac.uk).

SPSS for Windows Base System User's Guide Release 6.0

ISBN 0-13-178856-6

A good overview of the basic facilities in SPSS for Windows. It describes the:

Data Editor

Output and Syntax windows

Graph windows

Chart Carousel

Help system

Glossary

Also included are descriptions of the simpler statistical techniques, how they work and the assumptions that they make:

Descriptive Statistics

Cross Tabulation

Multiple Responses

Simple Hypothesis Tests

Analysis of Variance

Correlation

Simple and Multiple Regression

Non-Parametric Statistics

Charts and Graphs

SPSS for Windows Professional Statistics Release 6.0

ISBN 0-13-178831-0

A good overview of the slightly more advanced statistical facilities in SPSS for Windows It describes how they work and the assumptions that they make. This is essential reading for using most of these techniques:

Discriminant Analysis

Factor Analysis and Principle Components Analysis

Cluster Analysis

Reliability Analysis

Multidimensional Scaling

Weighted Least Squares

Two-Stage Least Squares

SPSS for Windows Advanced Statistics Release 6.0

ISBN 0-13-178823-X

A good overview of the most advanced statistical facilities in SPSS for Windows. It describes how they work and the assumptions that they make. This is essential reading for using most of these techniques:

Logistic Regression

Factorial Analysis of Variance

Multivariate Analysis of Variance

Repeated Measures Analysis of Variance

Hierarchical Loglinear Models

Non-Linear Regression

Probit Analysis

Life Tables

Kaplan-Meier Survival Analysis

Cox Regression

SPSS for Windows Trends Release 6.0

ISBN 0-13-179383-7

A good overview of the Time Series facilities in SPSS for Windows. It describes how they work and the assumptions that they make. This is essential reading for using these techniques.

SPSS for Windows Tables Release 6.0

ISBN 0-13-177783-1

A good overview of the advanced tabulation facilities in SPSS for Windows. It describes how they work and the assumptions that they make. This is essential reading for using these techniques.

SPSS Base System Syntax Reference Guide Release 6.0

ISBN 0-13-179391-8

A description of the SPSS command language which is not essential for Windows users. It is intended for those who prefer a command style of working to a menu and dialog style or for those who wish to do complex things that the menu system cannot cope with.

SPSS 6.1 for Windows Update

ISBN 0-13-182338-8

A good overview of the basic facilities in SPSS for Windows. It describes the:

Data Editor

Output and Syntax windows

Graph windows

Chart Carousel

Help system

Glossary

It also contains descriptions of the Windows-specific enhancement from version 6.0 to 6.1. It contains full details of enhancements to the Chart facilities, the new one-sample t-test procedure and the General Loglinear Analysis procedure from the Advances Statistics module.

SPSS 6.1 Base System User's Guide Part 2

ISBN 0-13-438870-4

This manual contains descriptions of the simpler statistical techniques, how they work and the assumptions that they make:

Descriptive Statistics

Cross Tabulation

Multiple Responses

Simple Hypothesis Tests

Analysis of Variance

Correlation

Simple and Multiple Regression

Non-Parametric Statistics

Charts and Graphs

SPSS 6.1 for Windows Base System User's Pack

ISBN 0-13-185208-6

This is a pack containing the above two manuals at rather less than the combined price of the two separately.

SPSS Professional Statistics 6.1

ISBN 0-13-190125-7

A good overview of the slightly more advanced statistical facilities in SPSS. It describes how they work and the assumptions that they make. This is essential reading for using most of these techniques:

Discriminant Analysis

Factor Analysis and Principle Components Analysis

Cluster Analysis

Reliability Analysis

Multidimensional Scaling

Weighted Least Squares

Two-Stage Least Squares

SPSS Advanced Statistics 6.1

ISBN 0-13-200065-2

A good overview of the most advanced statistical facilities in SPSS. It describes how they work and the assumptions that they make. This is essential reading for using most of these techniques:

Logistic Regression

Factorial Analysis of Variance

Multivariate Analysis of Variance

Repeated Measures Analysis of Variance

Hierarchical Loglinear Models

Non-Linear Regression

Probit Analysis

Life Tables

Kaplan-Meier Survival Analysis

Cox Regression

SPSS Tables 6.1

ISBN 0-13-200834-3

A good overview of the advanced tabulation facilities in SPSS. It describes how they work and the assumptions that they make. This is essential reading for using these techniques.

Stub and banner tables

Contingency tables

Multiple response data

SPSS Trends 6.1

ISBN 0-13-201055-0

A good overview of the forecasting and time series facilities in SPSS. It describes how they work and the assumptions that they make. This is essential reading for using these techniques:

Multiple curve fitting

Smoothing

Autoregressive functions

ARIMA

X11ARIMA

SPSS Categories 6.1

ISBN 0-13-182320-5

A good overview of the facilities for conjoint analysis and optimal scaling in SPSS. It describes how they work and the assumptions that they make. This is essential reading for using these techniques.

Conjoint analysis

Optimal scaling

Coorespondence analysis

Homogeneity analysis

Non-linear principal components analysis

Non-linear canonical correlation analysis

SPSS 6.1 Syntax Reference Guide

ISBN 0-13-438250-1

A description of the SPSS command language which is not essential for Windows or Macintosh users. It is intended for those who prefer a command style of working to a menu and dialog style or for those who wish to do complex things that the menu system cannot cope with.