an introduction to spss 19 - webs · spss limits you to a name between 1-8 characters long....

AN INTRODUCTION TO

SPSS

www.danielboduszek.com d.boduszek@hud.ac.uk

Daniel Boduszek University of Huddersfield

Outline

Beginning SPSS session

Defining the variables

Entering and modifying data

Useful SPSS features

Screening & cleaning the data

Beginning SPSS session

Click on the SPSS shortcut button on your desktop. OR

Go to START, click on All PROGRAMS, and click on SPSS

Basics

Toolbar: contains icons to facilitate easy point and click operations

Open files Undo last operation

Save data Redo last operation

Print file Insert case

Find data Insert variable

Basics

Menu Bar: provides a series of “drop down” commands to perform most essential SPSS functions.

File: These are the basic file management operations.

e.g. opening, saving, and printing files

Edit: This allows you to perform editing functions on the current data set.

e.g. cut, copy, clear, undo changes and redo changes

View: Allows you to change the current view of data, as well as toolbar options.

e.g. grid lines, value labels

Data: These functions deal with the configuration, defining, and management of data.

e.g. insert variables/cases, sort data, merge files

Transform: This allows you to transform the data set you’ve entered.

e.g. calculating new variables, recoding, missing values

Analyze: Includes the main data analysis functions.

e.g. descriptive statistics, t-Tests, ANOVA, correlation

Defining the variables

Variable View – define your variables

Data View - enter your raw data

Procedure for defining variables

Click on Variable View

Each row represents a different variable that you will use in your analysis.

At the very least you need to enter a name for each variable

SPSS limits you to a name between 1-8 characters long.

Procedure for defining variables

TYPE

The default is numeric data.

The most common format change is to “string” data, which will allow you to enter words rather than numbers.

Procedure for defining variables

Width

This allows you to set the maximum number of digits (or letters in a string format) you can enter in cell.

The decimal and all decimal points count as digits in the width.

Procedure for defining variables

DECIMALS

This indicates how many decimal points you can have in your cell.

Procedure for defining variables

LABEL

Because the variable name can only be 8 characters long, you can enter a longer description of the variable here.

Procedure for defining variables

Values – define the meaning of the values you have used to code your variables

Click on the 3 dots on the right-hand side of the cell. This opens Value Label box

Click in box Value. Type in 1.

In Label box tape “NonV” (Non-violent offenders)

Click on Add

Repeat for Violent offenders

Click OK

Procedure for defining variables

Missing – missing value (-9)

Columns – set at 8

Align – set at Right

Procedure for defining variables

Measure – level of measurement Scale (interval or ratio)

Nominal (categorical)

Ordinal (ranking data)

Entering Data

Click on Data View tab at the bottom left hand side of the SPSS window

A spreadsheet should appear with your defined variable names listed across the top

Click on the first cell of the data set and type in the number (value)

Participants

Modifying the data file

Delete a case – move down to the case (row) and press Delete button

Insert a case between existing cases – move cursor to a cell (row) immediately below where you want the new case to appear

Click on Edit menu and Insert Cases

Delete variable – highlight the variable (column) and press Delete

Insert a variable between existing variables - move cursor to a variable (column) to the right of where you want the new variable to appear.

Click on Edit menu and Insert Variable

Useful SPSS Features

Split the data file – to run analysis for groups (violent offenders and non-violent offenders) Click on the Data menu and Split File

Click on Compare groups and specify the grouping variable (e.g. Type of criminal)

Click OK

Useful SPSS Features

Select Cases – e.g. only violent offenders in your analysis Click Data and Select Cases option

Click If condition is satisfied button

Click If

Useful SPSS Features

Choose the group variable (type of criminals) and move into the box

Click on the “=“ key and type in the value that corresponds to the group you are interested in

This example - Violent offenders = 2 Click Continue Click OK

Screening & Cleaning the Data

Step 1: Checking the Errors Checking categorical variables

Analyse, then click on Descriptive Statistics, then Frequencies

Screening & Cleaning the Data

Choose the variable and move it into Variable box

Screening & Cleaning the Data

Click on Statistics.

Tick Minimum and Maximum in the Dispersion section

Click Continue and OK

Check your Minimum and Maximum – Do they make sense?

Check Valid and Missing cases

Screening & Cleaning the Data

Statistics

Type of Criminals

N Valid 89

Missing 0

Minimum 1.00

Maximum 2.00

Type of Criminals

Frequency Percent Valid Percent

Cumulative

Percent

Valid 1.00 NonV 45 50.6 50.6 50.6

2.00 Violant 44 49.4 49.4 100.0

Total 89 100.0 100.0

Screening & Cleaning the Data

Checking continuous variables Analyze, then Descriptive statistics, then Descriptives.

Move your continuous variable into Variables box

Screening & Cleaning the Data

Click Options button

Click on the statistics

you wish to generate

Continue

OK

Screening & Cleaning the Data

Check the Minimum and Maximum values

Check the Mean

Screening & Cleaning the Data

Descriptive Statistics

N Minimum Maximum Mean Std. Deviation

Criminal Thinking 89 10.00 43.00 29.1685 7.90747

Valid N (listwise) 89

Case Summaries – allows you to select and display specific

pieces of information for each case

Analyze, go to Reports and choose Case Summaries

Screening & Cleaning the Data

Choose ID variable and other variables.

Remove the tick from the Limit cases to first 100

Screening & Cleaning the Data

Click on the Statistics and remove Number of cases from the Cell Statistics

Click Continue

Screening & Cleaning the Data

Click on Options and remove the tick from Subheadings for totals

Continue

OK

Screening & Cleaning the Data

SPSS Output

Screening & Cleaning the Data

Case Processing Summary

Cases

Included Excluded Total

N Percent N Percent N Percent

ID Number 89 100.0% 0 .0% 89 100.0%

Age 88 98.9% 1 1.1% 89 100.0%

Type of Criminals 89 100.0% 0 .0% 89 100.0%

Level of Recidivism 89 100.0% 0 .0% 89 100.0%

Criminal Thinking 89 100.0% 0 .0% 89 100.0%

Neuroticism 89 100.0% 0 .0% 89 100.0%

Extraversion 89 100.0% 0 .0% 89 100.0%

Psychoticism 89 100.0% 0 .0% 89 100.0%

Parental Supervision 89 100.0% 0 .0% 89 100.0%

Criminal Identity 89 100.0% 0 .0% 89 100.0%

Criminal Identity2 89 100.0% 0 .0% 89 100.0%

Criminal Identity3 89 100.0% 0 .0% 89 100.0%

Case Summaries

ID Number Age

Type of

Criminals

Level of

Recidivism

Criminal

Thinking Neuroticism Extraversion Psychoticism

Parental

Supervision Criminal Identity

Criminal

Identity2

Criminal

Identity3

1 1 3 36 and

more

2.00 Violant 3.00 35.00 5.00 6.00 3.00 12.00 25.00 30.00 40.00

2 2 2 26 - 35 1.00 NonV 3.00 40.00 1.00 4.00 6.00 12.00 25.00 30.00 40.00

3 3 2 26 - 35 1.00 NonV 3.00 32.00 3.00 5.00 3.00 10.00 22.00 32.00 40.00

4 4 3 36 and

more

1.00 NonV 4.00 24.00 3.00 5.00 1.00 23.00 17.00 27.00 37.00

5 5 3 36 and

more

1.00 NonV 1.00 10.00 1.00 3.00 2.00 24.00 -9.00 -9.00 -9.00

6 6 3 36 and

more

1.00 NonV 3.00 35.00 5.00 1.00 1.00 11.00 33.00 38.00 40.00

7 7 3 36 and

more

1.00 NonV 3.00 37.00 4.00 1.00 2.00 17.00 8.00 12.00 20.00

8 8 3 36 and

more

1.00 NonV 8.00 23.00 4.00 4.00 1.00 14.00 16.00 26.00 29.00

9 9 3 36 and

more

1.00 NonV 2.00 15.00 2.00 1.00 .00 18.00 21.00 31.00 40.00

10 10 2 26 - 35 2.00 Violant 1.00 23.00 6.00 4.00 1.00 8.00 22.00 32.00 40.00

11 11 2 26 - 35 2.00 Violant 1.00 21.00 3.00 1.00 2.00 15.00 18.00 28.00 38.00

12 12 2 26 - 35 2.00 Violant 4.00 41.00 5.00 6.00 1.00 12.00 21.00 28.00 38.00

13 13 3 36 and

more

2.00 Violant 2.00 27.00 .00 6.00 2.00 13.00 14.00 24.00 34.00

14 14 2 26 - 35 2.00 Violant 6.00 35.00 4.00 5.00 1.00 12.00 19.00 29.00 39.00

15 15 1 18 - 25 2.00 Violant 2.00 40.00 6.00 3.00 1.00 17.00 35.00 38.00 40.00

16 16 1 18 - 25 1.00 NonV 2.00 34.00 1.00 6.00 6.00 9.00 -9.00 -9.00 -9.00

17 17 2 26 - 35 1.00 NonV 4.00 24.00 3.00 6.00 1.00 13.00 13.00 23.00 25.00

18 18 2 26 - 35 1.00 NonV 3.00 37.00 6.00 6.00 3.00 13.00 30.00 35.00 40.00

19 19 1 18 - 25 2.00 Violant 2.00 42.00 4.00 6.00 4.00 15.00 23.00 33.00 40.00

20 20 3 36 and

more

1.00 NonV 10.00 43.00 5.00 6.00 3.00 13.00 26.00 36.00 40.00

21 21 2 26 - 35 1.00 NonV 1.00 28.00 2.00 3.00 2.00 14.00 21.00 31.00 40.00

22 22 1 18 - 25 1.00 NonV 2.00 28.00 2.00 5.00 1.00 14.00 12.00 22.00 32.00

23 23 1 18 - 25 1.00 NonV 2.00 31.00 2.00 6.00 2.00 10.00 18.00 28.00 38.00

24 24 1 18 - 25 2.00 Violant 4.00 27.00 1.00 6.00 1.00 15.00 20.00 30.00 40.00

25 25 3 36 and

more

1.00 NonV 1.00 36.00 5.00 3.00 1.00 17.00 19.00 29.00 39.00

26 26 3 36 and

more

2.00 Violant 1.00 25.00 .00 5.00 3.00 16.00 8.00 18.00 28.00

27 27 2 26 - 35 1.00 NonV 2.00 21.00 3.00 4.00 1.00 13.00 10.00 20.00 30.00