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    Introduction to SPSS

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    Object of the Course

    •  About the four-windows in SPSS

    • The basics of managing data files

    • The basic analysis in SPSS

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    Introduction: What is SPSS?

    • SPSS (Statistical Product and Service Solutions)is a statistical software that enables us to perform

    statistical procedures easily, quickly and

    accurately.

    • SPSS has four windows: 

    Data editor

    Output viewer  

    Syntax editorScript window

    • Today, we will use only two of them.

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    • Data EditorSpreadsheet-like system for defining, entering, editing,

    and displaying data. Extension of the saved file will be“.sav”

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    • Output Viewer

    Displays output and errors. Extension of the saved file willbe “.spv” 

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    The basics of managing

    data files

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    Opening SPSS

    • Start → All Programs → IBM SPSS Statistics → → IBMSPSS Statistics 20

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    The first time you run SPSS, the following window will appear.

    You can chose one of the given options there. In the meantime click Cancel.

    Opening SPSS

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    Opening SPSS

    • The default window will have the data editor

    • There are two sheets in the window:

    1. Data view 2. Variable view 

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    Data View window

    This sheet is visible when you first open the Data Editor andthis sheet contains the data

    It has two views: Data view and Variable view

    Click

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    Variable View window

    • This sheet contains information about the data set that is stored

    with the dataset • Name

     – The first character of the variable name must be alphabetic

     – Variable names must be unique, and have to be less than 64characters.

     – Spaces are NOT allowed.

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    Variable View window: Type

    • Type

     – Click on the ‘type’ box. The two basic types of variablesthat you will use are numeric and string.

     

    This column

    enables you to specify the type of variable.

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    Variable View window: Width

    • Width

     – Width allows you to determine the number ofcharacters SPSS will allow to be entered for thevariable

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    Variable View window: Decimals

    • Decimals – Number of decimals

     – It has to be less than or equal to 16

    3.14159265

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    Variable View window: Label

    • Label

     – You can specify the details of the variable

     – You can write characters with spaces up to 256

    characters

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    Variable View window: Values

    • Values

     – This is used and to suggest which

    numbers represent which categories when

    the variable represents a category

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    Defining the value labels

    • Click the cell in the values column as shown below

    • For the value, and the label, you can put up to 60

    characters.

    •  After defining the values click add and then click OK.

    Click

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    Practice 1

    • How would you put the following information into

    SPSS?

    Value = 1 represents Male and Value = 2 represents Female

    Name  Gender Height 

    JAUNITA 2 5.4SALLY 2 5.3

    DONNA 2 5.6

    SABRINA 2 5.7

    JOHN 1 5.7

    MARK 1 6ERIC 1 6.4

    BRUCE 1 5.9

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    Practice 1 (Solution Sample)

    Click 

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    Click

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    Saving the data

    • To save the data file you created simply click ‘file’ and

    click ‘save as.’ You can save the file in different forms

    by clicking “Save as type.” 

    Click

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    Sorting the data

    • Click ‘Data’ and then click Sort Cases 

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    Sorting the data (cont’d) 

    • Double Click ‘Name of the students.’ Then clickok.

    Click

    Click

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    Practice 2

    • How would you sort the data by the‘Height’ of students in descending order? 

    •  Answer

     – Click data, sort cases, double click ‘height of

    students,’ click ‘descending,’ and finally clickok.

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    Transforming data

    • Click ‘Transform’ and then click ‘Compute Variable…’ 

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    Transforming data (cont’d) 

    • Example: Adding a new variable named ‘lnheight’ which is

    the natural log of height

     – Type in lnheight in the ‘Target Variable’ box. Then type in

    ‘ln(height)’ in the ‘Numeric Expression’ box. Click OK 

    Click

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    Transforming data (cont’d) 

    • A new variable ‘lnheight’ is added to the table 

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    Practice 3

    • Create a new variable named “sqrtheight”which is the square root of height.

    •  Answer

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    • Frequencies – This analysis produces frequency tables

    showing frequency counts and percentagesof the values of individual variables.

    • Descriptives

     – This analysis shows the maximum, minimum,mean, and standard deviation of the variables

    • Linear regression analysis

     – Linear Regression estimates the coefficientsof the linear equation

    The basic analysis

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      Opening the sample data

    • Open ‘Employee data.sav’ from the SPSS 

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    Opening the sample data

    • Go to “File,” “Open,” and Click Data• Go to Program Files,” “SPSSInc,” “IBMStatistics,”

    and “Samples” folder. 

    • Open “Employee Data.sav” file 

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    Frequencies

    • Click ‘Analyze,’ ‘Descriptive statistics,’ then

    click ‘Frequencies’ 

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    Frequencies

    • Click gender and put it into the variable box.

    • Click ‘Charts.’

    • Then click ‘Bar charts’ and click ‘Continue.’ 

    Click  Click

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    Frequencies

    • Finally Click OK in the Frequencies box.

    Click 

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    Using the Syntax editor

    • Click ‘Analyze,’ ‘Descriptive statistics,’ thenclick ‘Frequencies.’ 

    • Put ‘Gender’ in the Variable(s) box. 

    • Then click ‘Charts,’ ‘Bar charts,’ and click

    ‘Continue.’ • Click ‘Paste.’ 

    Click

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    Using the Syntax editor

    • Highlight the commands in the Syntax editorand then click the run icon.

    • You can do the same thing by right clicking the

    highlighted area and then by clicking ‘Run

    Current’ 

    ClickRightClick!

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    Practice 4

    • Do a frequency analysis on the variable“minority” 

    • Create pie charts for it

    • Do the same analysis using the syntax

    editor

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     Answer

    Click

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    Descriptives

    • Click ‘Analyze,’ ‘Descriptive statistics,’ thenclick ‘Descriptives’ 

    • Click ‘Educational level’ and ‘Beginning

    Salary,’ and put it into the variable box. 

    • Click Options

    Click

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    Descriptives

    • The options allows you to analyze otherdescriptive statistics besides the mean and Std.

    • Click ‘variance’ and ‘kurtosis’ 

    • Finally click ‘Continue’ 

    Click

    Click

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    Descriptives

    • Finally Click OK in the Descriptives box. You willbe able to see the result of the analysis.

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    Normal Distribution

    I) Area under the normal distribution (CDF)

    Example: Find the area to the left of 1 in thestandard normal distribution.

    Example: Suppose that the scores in a Stat

    course follows a normal distribution with mean70 and a standard deviation 10. Find the

    percentage of scores less than 78.

    Transform Compute CDF & Noncentral

    CDF

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    Normal Distribution

    II) The inverse function for the normal distribution

    Example: Find the 20th percentile in the previousexample.

    Transform Compute Inverse DF

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    Testing Hypothesis

    I) One sample T-Test

    Example: In order to determine the number of

    workers required to meet demand, the

    productivity of newly hired trainees is studied. It

    is believed that trainees can process and

    distribute more than 450 packages per hour

    within one week of hiring. Can we conclude that

    this belief is correct, based on productivity

    observation of 50 trainees, See worksheet

    “Productivity”.

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     Analyze Compare Means One-Sample T-Test

    1) The hypotheses are:

    H0:m ≤ 450 and Ha: m > 450

    2) Assumptions: we have large sample (n=50)

    3) t=1.894) P-value=0.065=0.0323

    5) Since 0.0323 < .05, we reject H0. The

    trainees can process and distribute more

    than 450 packages per hour within one weekof hiring.

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     Analyze

     Compare Means

     One-Sample T-Test

    Confidence Intervals

    Test value should be zero

    Click Options to set confidence level.

    In the previous example, calculate 95% for

    the true mean of the number of packages

    that trainees can process and distribute perhour within one week of hiring.

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    Regression Analysis

    • Click ‘Analyze,’ ‘Regression,’ then click

    ‘Linear’ from the main menu. 

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    Regression Analysis

    • For example let’s analyze the model• Put ‘Beginning Salary’ as Dependent and ‘Educational Level’ as

    Independent.

              edusalbegin 10

    ClickClick

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    Regression Analysis

    • Clicking OK gives the result

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    Practice 5

    • Find out whether or not the previousexperience of workers has any affect

    on their beginning salary?

     – Take the variable “salbegin,” and“prevexp” as dependent and independent

    variables respectively.