Getting started with SPSS, defining variables, entering data and importing data from Excel

1. Part 1:
Getting started entering data and defining variables
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2. Dr.ChristinePereira
» Purpose and use of SPSS
» Open SPSS
» What is a Variable?
» Defining variables in SPSS
» Entering Data
» Open and save data files
» Import data from Excel
» Handling missing data
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3. Dr.ChristinePereira
» SPSS is a Statistical Software Package
» SPSS is a tool
It only does what it’s ‘told’ to do.
It does not think for you
It is not a black box
» You need to know the correct statistics for your
research BEFORE using SPSS.
» If you understand the statistics, then you are ready to
do analysis in SPSS.
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4. Click on the Windows
Start Icon
Type SPSS 20 into the
search box
Select SPSS 20
from the list
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2
3
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5. Open NEW
data file
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Enter variable names in the
first column of Variable View.

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Enter the data for each variable.
Each variable name will appear as a
column heading replacing var.

8. What is a variable?
How do we define variables in SPSS?
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9. Dr.ChristinePereira
» A measurement:
A characteristic
+ E.g., Gender, Age, Height, Weight…
Time points
+ E.g., pre-test, post-test, T0, T1, T2…
Experimental Condition
+ E.g., Condition, Experimental group…
Opinion/belief
+ E.g., A survey question which asks for a respondent’s level of
agreement with a statement
Etc…
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What is your gender?
Male or Female

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How long does it take, on
average, to commute into Uni?

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What is your main mode
of transport to Uni?

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Indicate your level of agreement with this statement:
“Most days, my commute causes me to feel stressed when I
arrive at university”.

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» Random sample of 200 residents of Uxbridge.
» Asked respondents’ their view on stem cell research
using a 3 pt. Likert Scale (Disagree, No Opinion, Agree).
» Asked respondents’ if they believed global warming
was an important issue using a 5 pt. Likert Scale
(Strongly Disagree to Strongly Agree).
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Questionnaire Responses

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» Random sample of 200 residents of Uxbridge.
» Asked respondents’ their view on stem cell research
using a 3 pt. Likert Scale (Disagree, No Opinion, Agree).
» Asked respondents’ if they believed global warming
was an important issue using a 5 pt. Likert Scale
(Strongly Disagree to Strongly Agree).
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Questionnaire Responses

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Resident StemCell GlobalWarming
1 Agree Strongly Agree
2 Undecided Agree
3 Undecided Strongly Disagree
4 Disagree Undecided
… … …
Questionnaire Responses

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Experimental Condition
Cond 1 and 2 are independent,
NOT repeated measures.

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Score on a test

19. Dr.ChristinePereira
» 30 participants were used to investigate the effect of
caffeine on their ability to sleep.
» The 30 participants were randomly assigned to one of 2
conditions: No caffeine (control) or one dose of caffeine
every 3 hours from 9am-6pm.
» The study measured participants ability to sleep by
taking the average number of hours slept per night
over a 2 week period.
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Caffeine and Sleep

20. Dr.ChristinePereira
» 30 participants were used to investigate the effect of
caffeine on their ability to sleep.
» The 30 participants were randomly assigned to one of 2
conditions: No caffeine (control) or one dose of caffeine
every 3 hours from 9am-6pm.
» The study measured participants ability to sleep by
taking the average number of hours slept per night
over a 2 week period.
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Caffeine and Sleep

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Participant Condition AvgHoursSlept
1 Control 7.2
2 Caffeine 6.7
3 Caffeine 6.3
4 Control 6.9
… … …
Caffeine and Sleep

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Status when admitted
to care facility

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Anxiety level measured at
3 time points for each participant

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Why not enter TIME
as 1 variable like we
did for STATUS?

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» 50 participants of varying fitness levels were used to
investigate whether personal trainers make a significant
difference in ones fitness.
» Participants were randomly assigned to one of two
training groups: self training or professional trainer.
» Each participants 1 mile time (in mins) was recorded 2
days prior to the start of the study.
» Each group then followed a specific training regime for
30 days and their 1 mile time (in mins) recorded again.
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Fitness Regime

26. » 50 participants of varying fitness levels were used to
investigate whether personal trainers make a significant
difference in ones fitness.
» Participants were randomly assigned to one of two
training groups: self training or professional trainer.
» Each participants 1 mile time (in mins) was recorded 2
days prior to the start of the study.
» Each group then followed a specific training regime for
30 days and their 1 mile time (in mins) recorded again.
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Fitness Regime
Pre-test and Post-test

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Fitness Regime
Participant Training Pre_Mile Post_Mile
1 Self 15.3 14.1
2 Professional 16.1 14.9
3 Self 20.5 16.8
4 Self 16.8 16.2
… … … …

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Variables
Categorical
Qualitative
Scale
Quantitative
Nominal
(Unranked categories)
 Marital Status
 Political Party
 Eye Color
Ordinal
(Ranked categories)
 Satisfaction level
 Level of agreement
Not grouped
 Height
 Weight
 Age
 No. of cars
 No. of students
• In SPSS, data is either Nominal, Ordinal or Scale.
• It is essential to classify data correctly.
- Incorrect classification…
may result in incorrect analyses.

29. Code categorical variables
Enter data
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Level of
Measurement?
Categorical variables need to be coded
Scale variables do not need to be coded

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Level of
Measurement?
0 = Male
1 = Female
1
0
1
1
1
1
0
0
0
0

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Level of
Measurement?
Scale, does not
need to be coded

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1 = tfl (i.e. public transport)
2 = Car
3 = Cycle
4 = Walk
1
2
3
4
2
1
1
1
1
1
Level of
Measurement?

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Indicate your level of agreement with
the following statement:
“Most days, my commute causes me
to feel stressed when I arrive at
university”.

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1 = Strongly Disagree
2 = Disagree
3 = I don’t know
4 = Agree
5 = Strongly Agree
Level of
Measurement?

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Data has been coded
Now we’re ready to enter it in SPSS

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1. Enter & define variables from Variable View.
• Variable names
• Must begin with a letter
• No spaces and no special characters (except _ )

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1. Enter & define variables from Variable View.
• Type
• Should (almost) always be numeric
• SPSS cannot analyse non-numeric data

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1. Enter & define variables from Variable View.
• Decimals
• How many decimal places do you want to see in
the Data View?

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1. Enter & define variables from Variable View.
• Label
• IMPORTANT!!! Make good labels!
• Short description of the variable
• This is what will be written on all graphs & tables

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1. Enter & define variables from Variable View.
• Values (i.e., Value labels)
• IMPORTANT!!! - Tell SPSS what all the codes represent!
• This is what is written on all graphs & tables

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1. Enter & define variables from Variable View.

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1. Enter & define variables from Variable View.
• Missing
• Missing data can be coded too
• Chose a number not in the data, like 99 or 999
• Replace all missing values in your data with this code first

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1. Enter & define variables from Variable View.
• Measure
• Level of Measurement (Nominal, Ordinal, Scale)
• By default ALL new variables are unknown
• YOU must choose the appropriate measure

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2. Enter data from Data View.
• Variable names
• Will become column headings in Data View.

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Now, let’s enter some data

47. Saving and Opening Data or Output Files
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Locate a folder
to save it in:
On your H drive OR
On your pen drive
Name it appropriately
Extension .sav

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Everything done in
SPSS is shown here,
in outline form.
 Shows output for ALL analysis run in SPSS
 Keeps a log of all activity of open data files
 Saved with the extension .spv
A data file was saved as
SPSS Workshop Example.sav
and logged in the output file.

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New
data file
New
output file

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Existing
data file
Existing
output file

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Importing data from Excel

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Click here

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Click here
Save this file
to your H: drive
or pen drive

56. Dr.ChristinePereira
» Log onto Blackboard
» Go to the Organisation Academic Skills
» In the left column, under Workshop Presentations
Click on Statistics and SPSS
» Find the SPSS Workshop
Download the Excel File: “CommutingSurvey.xlsx”
» Save this file somewhere you can find it later.
» Do not open it. You cannot import the file if it’s open.
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57. Dr.ChristinePereira
» Can be .xls OR .xlsx
» Variable names CAN be imported too
Must be in row 1 of the worksheet
They will be imported to the Variable View
» Data will appear in SPSS Data View
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Variable
names
(Row 1)
Filename
(.xlsx)
This sheet contains the dataset

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Existing
data file
Dr.ChristinePereira

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Choose Excel file type to
see your .xlsx
Find the folder
where you
saved the fileSelect the
Excel file
3
1
2

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Choose the
correct
worksheet

62. View all data
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Variable
Names
(from Row 1)

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This variable name from Excel could
not be used. SPSS made it a label and
created a new variable name

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How to handle missing data

65. Dr.ChristinePereira
» Any blank (i.e., missing) data is automatically
considered missing by SPSS.
It will not be included in the analysis.
This means you DO NOT have to code missing data
» Why code missing values if you don’t have to?
Sometimes data accidently gets deleted. If missing values are
coded then you know a blank space shouldn’t be there.
There is more than one reason data is missing and you want
to distinguish between them.
+ E.g., A participant chose not to answer a survey question or question
was not applicable to them – you may want to record these as
different kinds of missing data.
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There are 3 missing
values for
TravelTimemin
• Replace missing values with a code
• Use a code that will not occur for the variable
• Let’s use -1, as negative time is not possible

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1

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3
Select the
variable you
want to recode
Click here to
recode the
variable
2

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4
Enter the
code as the
new value
Click Add.
MISSING -> -1
will appear here
5
6
Click Continue
then Click OK
7

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Missing values
have been
replaced with -1
for TravelTimemin

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Remember…
From Variable View
Define the missing values
8
• Discrete (whole numbers)
• Enter missing value codes used for the variable (e.g., -1)
• Click OK

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This is only a code – it tells SPSS what value(s) represent
missing values.
It does not replace missing values with the code for you!

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» Variables go in columns
» Categorical data should be coded first
» If you import data from Excel, make sure to:
Put variable names in the first row
Code your categorical data first, then import codes
» If you choose to code missing data:
First, replace all missing values with the code
Second, define the missing value code in the Variable View
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74. Dr.ChristinePereira
» SPSS Survival Manual, 4th Edition (2010) by Julie Pallant.
» SPSS Survival Manual, 5th Edition (2013) by Julie Pallant.
» Discovering Statistics Using SPSS, 3rd Edition (2009) by Andy Field.
» Discovering Statistics Using SPSS, 4th Edition (2013) by Andy Field.
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