Dr. Engr. Sami ur Rahman Research Methods in Computer Science Lecture: Data Analysis (Introduction to SPSS)

Courtesy Kevin Schoepp (Zayed University) Kentaka Aruga University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 2

Introduction: What is SPSS?  Originally it is an acronym of Statistical Package for the Social Science but now it stands for Statistical Product and Service Solutions  One of the most popular statistical packages which can perform highly complex data manipulation and analysis with simple instructions University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 3

Data Editor  Data Editor Spreadsheet-like system for defining, entering, editing, and displaying data. Extension of the saved file will be “sav.” University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 4

Output Viewer  Output Viewer Displays output and errors. Extension of the saved file will be “spv.” University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 5

The basics of managing data files University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 6

Opening SPSS  The default window will have the data editor  There are two sheets in the window: 1. Data view2. Variable view University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 7

Data View window  The Data View window This sheet is visible when you first open the Data Editor and this sheet contains the data  Click on the tab labeled Variable View Click University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 8

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 64 characters.  Spaces are NOT allowed. University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 9

Variable View window: Type  Type  Click on the ‘type’ box. The two basic types of variables that you will use are numeric and string. This column enables you to specify the type of variable. University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 10

Variable View window: Width  Width  Width allows you to determine the number of characters SPSS will allow to be entered for the variable University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 11

Variable View window: Decimals  Decimals  Number of decimals  It has to be less than or equal to 16 University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 12

Variable View window: Label  Label  You can specify the details of the variable  You can write characters with spaces up to 256 characters University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 13

Variable View window: Values  Values  This is used and to suggest which numbers represent which categories when the variable represents a category University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 14

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 University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 15

Practice 1  How would you put the following information into SPSS? Value = 1 represents Male and Value = 2 represents Female University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 16

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 University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 17

Sorting the data  Click ‘Data’ and then click Sort Cases University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 18

Sorting the data (cont’d)  Double Click ‘Name of the students.’ Then click ok. Click University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 19

Transforming data  Click ‘Transform’ and then click ‘Compute Variable…’ University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 20

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 University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 21

Transforming data (cont’d)  A new variable ‘lnheight’ is added to the table University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 22

Opening the sample data  Open ‘Employee data.sav’ from the SPSS  Go to “File,” “Open,” and Click Data  University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 23

Opening the sample data  Go to Program Files,” “SPSSInc,” “SPSS16,” and “Samples” folder.  Open “Employee Data.sav” file University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 24

Frequencies  Click ‘Analyze,’ ‘Descriptive statistics,’ then click ‘Frequencies’ University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 25

Frequencies  Click gender and put it into the variable box.  Click ‘Charts.’  Then click ‘Bar charts’ and click ‘Continue.’ Click  University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 26

Frequencies  Finally Click OK in the Frequencies box. Click University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 27

University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 28

University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 29

Descriptives  Click ‘Analyze,’ ‘Descriptive statistics,’ then click ‘Descriptives…’  Click ‘Educational level’ and ‘Beginning Salary,’ and put it into the variable box.  Click Options Click University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 30

Descriptives  The options allows you to analyze other descriptive statistics besides the mean and Std.  Finally click ‘Continue’ Click University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 31

Descriptives  Finally Click OK in the Descriptives box. You will be able to see the result of the analysis. University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 32

33 Running Analyses (Central Tendency) 26. Select the desired variables (household income) and click the arrow to move them to the right side 25. Select Analyze- Descriptive Stats- Frequencies University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 33

Running Analyses (Central Tendency) Results will appear 27. Select some measures of central tendency and dispersion- click Continue then OK University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 34

35 Running Analyses (Correlation) 28. Click Analyze- Correlate- Bivariate 29. Move the two variables of interest to the right side (age & income), click OK University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 35

36 Running Analyses (Correlation) 30. Results appear and tell us that the relationship is weak to moderate and results are not due to chance University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 36

University Of Malakand | Department of Computer Science | UoMIPS | Dr. Engr. Sami ur Rahman | 37 Thanks for your attention