How to use SPSS for analyzing basic quantitative research ...

1 How To Use spss For analyzing basic quantitative research QuestionsSUMMER INSTITUTE, 2016 Steven A. HechtMaria R. Ligas1 TODAY WE WILL: Discuss how to get spss rent it! Go over basics of spss Go over some popular analyses based on following examples of research questions:1. Was there significant improvement in reading scores between pretest and posttest?2. Were there significant differences between groups in reading scores?3. Were there significant differences between groups in Posttest reading scores while controlling for initial Pretested ability?4. Did group, pretested ability, and estimate IQ all uniquely predict Posttest reading scores? Discuss YOUR OWN research sign in and print your name and email address so that I can email you these notes!

2 3 GET IBM spss You can rent spss . Different options depending on the analysis you want to do and how long you plan to use IBM spss DATA FILE (.SAV) HAS TWO SCREENS Data view The place to enter data Columns: variables Rows: records Variable view The place to enter variables List of all variables Characteristics of all variables5 BEFORE THE DATA ENTRY You need a code book/scoring guide You give ID number for each case (NOT real identification numbers of your subjects) if you use paper survey. If you use online survey, you need something to identify your cases. You also can use Excel to do data entry. 6 ENTER DATA IN spss 7 Columns:variablesRows: casesData View TabENTER VARIABLES8 Under Va r i a b l e ViewENTER VARIABLES92.

3 Type variable name3. Type: numeric or string4. Description of variableENTER value LABELS FOR VARIABLES IF NEEDEDB ased on your code book!ENTER DATA FOR YOUR CASES11 Under Data ViewIMPORT DATA FROMEXCEL! Select File Open Data Choose Excelas file type Select the file you want to import Then click ok12 CLEAN DATA AFTER IMPORT DATA FILES Key in values and labels for each variable Run frequency for each variable Check outputs to see if you have variables with wrong values. Check missing values and physical surveys if you use paper surveys, and make sure they are really missing . Sometimes, you need to recode string variables into numeric variables13 research QUESTION #1: Was there significant improvement in reading scores for the same students between pretest and posttest?

4 14 PretestReading ScoresPosttest Reading Scores So, were the average reading scores different between pretest and posttest? Use the paired sample t-testIntervention or TreatmentPAIRED SAMPLE T-TEST15 Analyze -> compare means -> paired sample t-testPAIRED SAMPLE T-TEST16 Analyze -> compare means -> paired sample t-testSPSS Output file (.spv)PAIRED SAMPLE T-TEST17 Analyze -> compare means -> paired sample t-testSPSS OutputIf the value is .05 or smaller, then the difference is statistically significant! research QUESTION #2: Were there significant differences between two independent groups in math scores?18 Groups (IV)(Control vs. Treatment)DVReading scores So, were the average reading scores different between Control Group and Treatment Group?

5 You could use a t-test or Analysis of Variance. Lets use ANOVAANALYSIS OF VARIANCE19 Analyze -> general linear model -> univariateANALYSIS OF VARIANCE20 Analyze -> general linear model -> univariateHere is your predictorIf this value is .05 or less then effect is statistically significant research QUESTION #3: Were there significant differences between groups in posttest reading scores while controlling for initial pretested ability?21 IVGroups (control versus treatment)DVPosttest Reading You could use Analysis of Variance with a covariateCovariatePretest ReadingANALYSIS OF VARIANCE WITH A COVARIATE22 Analyze -> general linear model -> univariateANALYSIS OF VARIANCE WITH A COVARIATE23 Analyze -> general linear model -> univariateHere is group predictorIf this value is.

6 05 or less then effect is statistically significant covariate used to look at change in readingRESEARCH QUESTION #4: Did group, pretested ability, and estimate IQ all uniquely predict posttest reading scores?24 IVGroupsDVPosttest Reading You could use Analysis of Variance or REGRESSIONC ovariatePretest ReadingCovariateIQREGRESSION25 Analyze -> Regression-> LinearREGRESSION26 Analyze -> regression-> linearHere is Group predictorLook! Group is no longer significant!covariate used to look at change in readingcovariate used to control for IQWHY DID WE SHOW YOU REGRESSION?Useful when we do not have groups, but instead have several predictors of an outcome27 Letter KnowledgePosttest ReadingPretest ReadingIQMotivationVo c a b u l a r yPlease sign in and print your name and email address so that I can email you these notes!

7 28- What research questions do you have?- What kind of statistical analysis would be appropriate? 29