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SPSS Introductory Workshop. Humboldt State University May 6, 2011. Sponsors. and the http://www.ssric.org. College of Arts, Humanities and Social Sciences http://www.humboldt.edu/cahss /. SPSS Help Online.
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SPSS Introductory Workshop Humboldt State University May 6, 2011 www.ssric.org
Sponsors and the http://www.ssric.org College of Arts, Humanities and Social Sciences http://www.humboldt.edu/cahss/ www.ssric.org
SPSS Help Online SPSS for Windows 16.0: A Basic Tutorial by Linda Fiddler, Laura Hecht, Edward E. Nelson, Elizabeth Ness Nelson, and James Ross. Resources to Help You Learn and Use SPSS (UCLA) SPSS Tutorials (Texas A&M) www.ssric.org
SPSS A statistical package for beginning, intermediate, and advanced data analysis Other statistical packages include SAS and Stata Online statistical packages that don’t require site licenses include SDA www.ssric.org
Agenda • Introduction and Overview • A Brief Tour of SPSS • Creating Your Own SPSS Files or Opening Existing Datasets • Transforming data • Recode • Compute • Select If • Univariate analysis • Frequencies • Descriptives • Explore • Introduction to Graphics www.ssric.org
A Brief Tour of SPSS www.ssric.org
Data View www.ssric.org
Variable View Variable Names Variable Labels Value Labels MissingValues www.ssric.org
Menu Bar www.ssric.org
The Edit Menu www.ssric.org
The Edit Menu(continued) www.ssric.org
The Data Menu www.ssric.org
The Transform Menu www.ssric.org
The Analyze Menu www.ssric.org
The Graphs Menu www.ssric.org
Opening SPSS Go to start and find SPSS for Windows or look for the SPSS icon on your desktop. Click on SPSS 18.0 for Windows in the Start menu or double click on the icon. You’ll need to update your SPSS license every year (or your school technician will do it for you – Faculty/staff can load software on home computers). www.ssric.org
Opening an Existing File Often you will want to open a data set that you got from someplace else. These files will usually be in the form of a: SPSS portable file SPSS data file Raw data file with a SPSS syntax file Raw data file without a syntax file www.ssric.org
SPSS Files and Extensions Portable file -- .por Data file -- .sav Output file -- .spo Syntax file -- .sps www.ssric.org
Opening a Portable (.por) file Click on the open yellow folder to open a new file. Change file type to .por Browse to where the portable file you want to open is located and double click on that file. www.ssric.org
Opening a Text file Click on File > Read Text Data… In the Open Data window change file type
Opening an Existing SPSS System File Example: the 2010 General Social Survey • In browser, go to http://www.norc.org/GSS+Website/ • Select “Download” and “SPSS Format” www.ssric.org
Opening an Existing SPSS System File Example: the 2010 General Social Survey • Select “2010” www.ssric.org
Opening an Existing SPSS System File Example: the 2010 General Social Survey • Select “OK” to “Save File” • Double Click on “2010.sav” file www.ssric.org
Saving an Existing SPSS System File Example: the 2010 General Social Survey • Go to “File” and “Save As” and select “Variables” button • Select “Drop All” www.ssric.org
Saving an Existing SPSS System File Example: the 2010 General Social Survey • Select variables of interest: • Age • Cappun • Degree • Educ • Grass • Hrs1 • Hrsrelax • Income06 • Maeduc • Marital • Masei • Paeduc • partyid • Pasei • Realinc • Relig • Sei • Sex www.ssric.org
Saving an Existing SPSS System File Example: the 2010 General Social Survey • Select “Continue” and “Save” (to either desktop or your own flash drive) • We will continue to work with this same GSS 2010 data file during the workshop www.ssric.org
Opening an Existing SPSS System File Example: the 2008 General Social Survey • Open the file from network www.ssric.org
Opening an Existing SPSS System File (continued) • Opening the file: • Open from desktop (double-click) OR • Open SPSS first (as you would any windows program), then navigate to file. www.ssric.org
Move cursor to File Open Data Click on Data Navigate to file location (e.g., desktop) and open Opening an Existing SPSS System File (continued) www.ssric.org
Transforming Data We can transform variables by recoding, i.e., combining categories in an existing variable into fewer categories. We can also transform variables by creating new variables out of existing variables. We can select particular cases and analyze only these cases. www.ssric.org
Recoding into Different Variables Click on Transform > Recode > Into different variables. Select the variable you want to recode. age • Start by giving the new variable a new name (age1) • Click on Change • Click on Old and New Values www.ssric.org
Recoding age into AGE1 Use “Range” (fourth option down) to recode as follows. Remember to click on “Add” after entering each recode. 18 to 29 = 1 30 to 49 = 2 50 to 69 = 3 70 to 89 = 4 Click Continue And then OK.
Assign Value Labels to the Four Categories of AGE1 Select the Variable View tab. Scroll down the variables to age1 (at the bottom of the list). In the Values column of age1 click on the small gray box. Enter the first value followed by its label. Click Add. Enter remaining 3 values. Then click on OK. • 18 to 29 = 1 • 30 to 49 = 2 • 50 to 69 = 3 • 70 to 89 = 4
Exercises for Recoding Now recode income06 and call the new variable income2 This time use 8 categories: under $10K, $10K to under $20K, $20K to under $30K, $30K to under $40K, $40K to under $50K, $50K to under $60K, $60K to under $75K, and $75K and over Add the value labels Run a frequency distribution for income2 and check to make sure that you recoded it correctly by comparing the unrecoded and recoded frequency distributions
Creating a New Variable with Compute Let’s create a new variable and call it timewaste which is the percentage of relaxation time (hrsrelax) devoted to watching TV (tvhours) Click on Transform > Compute Enter the new variable name (timewaste) into the Target Variable box. Enter the formula for this new variable (100*tvhours/hrsrelax) into the Numeric Expression box. Click on OK www.ssric.org
Caution! • If, for any case, any of the variables used to create a new variable has a missing value, the new variable will automatically be assigned a missing value as well. www.ssric.org
Exercise for Compute The data file includes indexes of socio-economic status for respondents (sei), their mothers (masei) and their fathers (pasei). Create an index of mobility by subtracting sei from an average of masei and pasei. www.ssric.org
10 MINUTE BREAK! www.ssric.org
Using Select Cases to Select Specific Cases for Analysis Let’s select only Protestants for further analysis. Click on Data > Select Cases. Click on “If condition is satisfied” and then on the “If” button below it.
Using Select Cases to Select Specific Cases for Analysis Select the variable relig ( R’s RELIGEOUS PREFERENCE) and move it into the box on the right. In this box, enter the expression relig = 1. Click on Continue and on OK. www.ssric.org
Using Select Cases to Select Specific Cases for Analysis Note all cases not accepted are crossed out on the left. Again click on Data > Select Cases. Click on “all” and then OK. www.ssric.org
Important Note on Using Select Cases When you are finished using Select Cases and want to revert to using all the cases be sure to click on Data > Select Cases and select All cases. Then click on OK If you don’t do this, you will continue to use only those cases you last selected www.ssric.org
Exercises for Select Cases Select all males (1 on the variable sex) and do a frequency distribution for the variable partyid (political party identification) Now select all females (2 on the variable sex) and run a frequency distribution for partyid Is there a “gender gap” in party identification. How large is it? Note: same thing could have been done with Crosstabs www.ssric.org
Univariate Analysis Now that we know how to open existing files and transform variables, we’re ready to begin analyzing data Univariate analysis refers to analyzing variables one-at-a-time www.ssric.org
Types of UnivariateAnalysis Procedures Frequencies Descriptives Explore www.ssric.org
Frequencies Go to: Analyze > Descriptive Statistics > Frequencies Select age1 and age Notice Statistics and Charts buttons at upper right and Display frequencies tables check-box at lower left www.ssric.org
Frequencies: Statistics Click on Statistics Select the statistics you want Click on Continue www.ssric.org
Frequencies: Charts Click on Charts Select Histograms and check With normal curve Click on Continue Click on OK www.ssric.org
Frequencies: Output - Tables www.ssric.org