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.Questionnaire Development: SPSS and Reliability

Initial Tasks to Analyze Friend/Family Data – Google Docs and Excel 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!