Transcript Questionnaire Development: SPSS and Reliability

Questionnaire Development Part
II: SPSS, Reliability, and Validity
Personality Lab
October 11, 2010
Tasks for Analyzing Friend/Family Data
• Several tasks are identical to those completed in
the computer lab. For these, I’ll simply state
them in order to refresh your memory. For
additional review, click on the link to see
Friday’s slides called Questionnaire
Development: SPSS and Reliability or go to our
website.
Initial Tasks to Analyze Friend/Family
Data – Google Docs and Excel
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Open Google Docs Spreadsheet
Download Spreadsheet to Desktop in Excel
Format
Open Spreadsheet in Excel and Change
Column Headings from Questionnaire Items to
Short Variable Names: TIP – Name your
questionnaire items Q1-Q10 and name the
items for the validity questionnaire V1-V10 (or
V12, for example, if there are 12 items)
Save your excel file
Initial Tasks to Analyze Friend/Family
Data -- SPSS
• Open SPSS
• Click cancel on opening screen
• File > Open > Data – to open your Excel
spreadsheet in SPSS (remember the file type is
.xls and it is on your desktop)
• After your data opens up in SPSS, save it in case
you have problems later on (File > Save as >file
name)
Initial Tasks to Analyze Friend/Family
Data – Reverse Code Items
• In SPSS click Transform > Recode into same
variables
• Select items to reverse code
• Click on “Old and New Values”
• TIP – remember to reverse code your
questionnaire items and questions from the
“validity questionnaire.” If all are on same
response scale (e.g., 1-4), do all at the same time.
If different scales (e.g., 1-4 & 1-5), do separately
Run Reliability Analysis on Your
Questionnaire
• Analyze > Scale > Reliability Analysis
• Select items for analysis
• Click “Statistics” and check “item” and “scale if item
deleted”
• Click continue
• Click OK, See Output
• TIP – Run once on your questionnaire items. We’re
not revising, this is the finished product, so we run
once to determine final reliability of your
questionnaire. No need to run on validity
questionnaire
Beginning of New Tasks
• To finish your analysis, we need to do two tasks
that will be new to you
• First, we need to calculate the overall score for
your questionnaire and the validity
questionnaire.
• Second, we need to correlate your two
questionnaires.
• On to the first task
Total Up Scores for Each Questionnaire
• My example has 3 variables for my questionnaire
and 3 variables for the validity questionnaire
• We want to add up Q1, Q2, and Q3. Then add V1,
V2, and V3
Total Up Scores for Each
Questionnaire, cont.
• Go to Transform > Compute Variable
• I added up Q1, Q2 and Q3 and the total is called
MyHappy (you can name it anything you want)
Total Up Scores for Each
Questionnaire, cont.
• Click OK, SPSS calculates MyHappy
• Return to the SPSS Data and MyHappy shows up
Total Up Score for Validity Q
• Go to Transform > Compute Variable
• I added up V1, V2 and V3 and the total is called
ValidHappy (again, call it whatever you like)
Total Up Score for Validity Q, cont.
• Click OK, SPSS calculates ValidHappy
• Return to the SPSS Data and ValidHappy shows
up
• We now have scores for our two questionnaires
• Now for the last task
Correlate Your Questionnaire with
Validity Questionnaire
• I want to correlate MyHappy with ValidHappy
• Go to Analyze > Correlate > Bivariate
Output from Correlation Analysis
• Click OK, analysis runs, see output
• Correlation between MyHappy and ValidHappy is
r=.903 (that’s big). I made up the data. Your
correlation will probably be smaller
Your Analyses are Complete!!
• You should now have everything needed to
finish writing your questionnaire assignment.
• Pay close attention to the Instructions on the
Assignment sheet.
• Good Luck!