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SAS Global Forum 2008 presentation

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This is my SAS Student Ambassador presentation to the 2008 SAS Global Forum.

This is my SAS Student Ambassador presentation to the 2008 SAS Global Forum.

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SAS Global Forum 2008 presentation SAS Global Forum 2008 presentation Presentation Transcript

  • Reliability and Validity testing using SAS/STAT Andrea Roofe Ph.D. Candidate, Florida International University SAS ® Student Ambassador 2008
  • Reliability
    • Instrument consistently measures what it should measure.
    10 lbs of feathers 10 lbs of steel =
  • Validity
    • Accuracy
    • Reliability is a prerequisite for validity
    • Predictive ability
  • Research Questions
    • Are there differences between virtual and traditional teams?
    • If yes, what are they?
    • Implications for team management and
    • leadership
  • The Process
    • Instrument development
    • Discriminant Analysis
    • Logistic Regression
    • Factor Analysis
    • Reliability Testing
    • Descriptive Analysis
  • Instrument Development
    • Scale development procedures (DeVellis,2003)
    • 34 items
      • member perception of leader behaviors
      • member perception of group dynamics
    • Pilot survey using different groups
  • Descriptives
    • PROC UNIVARIATE
    • PROC MEANS
    • PROC FREQ
    • PROC UNIVARIATE PLOT NORMAL (not done for categorical variables)
    • OPTIONS LINESIZE=150 PAGESIZE=60 PAGENO=1;
    • TITLE1 'DATA ANALYSIS-VALIDATION OF SURVEY INSTRUMENT';
    • DATA COMBINEDAOM;
    • INFILE 'insert address of your input file';
    • INPUT list of variables ;
    • IF VIRTRAD=1 THEN TEAM='VIRTUAL';
    • ELSE TEAM='TRADITIONAL';
    • IF TYPETEAM=1 THEN TYPE='ACADEMIC';
    • IF TYPETEAM=2 THEN TYPE='STUDENT';
    • IF TYPETEAM=3 THEN TYPE='MANAGEMENT' ;
    • IF TYPETEAM=4 THEN TYPE='TECHNICAL';
    • IF TYPETEAM=5 THEN TYPE='OTHER';
    • *COMPUTING MEANS;
    • PROC MEANS DATA = COMBINEDAOM;
    • VAR Q1--GROUP;
    • RUN;
    • *COMPUTING BASIC STATISTICAL MEASURES-MODE, STD DEVIATION etc;
    • ODS;
    • PROC UNIVARIATE DATA=COMBINEDAOM;
    • VAR Q1--GROUP;
    • RUN;
    • PROC FREQ DATA=COMBINEDAOM;
    • RUN;
  • Reliability Analysis Code
    • Performed on both constructs
    • NOMISS Missing values ignored
    • ALPHA option in PROC CORR
    • PROC CORR DATA = ‘ name of file’ ;
    • ALPHA NOMISS;
    • VAR ‘list of variables’;
    • RUN;
    • PROC CORR DATA = ‘ name of file’ ALPHA NOMISS;
    • VAR ‘list of variables’; ;
    • RUN;
    • PROC CORR DATA = ‘ name of file’ ALPHA NOMISS;
    • VAR ‘list of variables’;
    • RUN;
  • Reliability Analysis Results
  • Factor Analysis Factor 1 Factor 2 Variable 1 Variable 2 Variable 3 Variable 4 Variable 5 Variable 6 Variable 7
  • Factor Analysis options
    • PROC FACTOR
    • METHOD=PRINCIPAL
    • SCREE
    • METHOD=ML
    • HEYWOOD
    • ROTATE=VARIMAX
  • Factor Analysis
    • Principal Components Method
    • Scree Plot
    • Maximum Likelihood Method
    • PROC FACTOR DATA= ‘ name of file ’ METHOD=principal SCREE ROTATE=varimax S C;
    • VAR ‘ list of variables ’;
    • RUN;
    • PROC FACTOR DATA= ‘ name of file ’ METHOD=ML HEYWOOD ROTATE=varimax S C;
    • VAR ‘ list of variables ’;
    • RUN;
  • Factor Analysis Results
    • Principal Components Method= 9 factors
    • Maximum Likelihood Method=11 factors
    • Scree plot=4 factors
    • 4 factors = approx. 50% of variance
  •  
  • Logistic Regression
    • DV is categorical
    • Normality assumption violated.
    • Press & Wilson (1978)
  • Logistic Analysis Code
    • Dummy variables using IF…ELSE
    • PROC LOGISTIC
    • MODEL (options STEPWISE, BACKWARD)
    • DATA Combinedaomfiuaib;
    • SET Combinedaomfiuaib;
    • IF VIRTRAD=1 THEN NEWVIRTRAD=1; ELSE NEWVIRTRAD=0;
    • PROC LOGISTIC DATA=Combinedaomfiuaib;
    • MODEL NEWVIRTRAD = country size lengthexist explifespan group survey teambuild comfrtgroup satwork cohesiv
    • /BACKWARD;
    • OUTPUT OUT=OUT1 PREDICTED=POSTERIOR;
    • TITLE2 'LOGISTIC REGRESSION ANALYSIS OF VIRTUAL TEAMS DATA';
    • RUN;
  •  
  • Discriminant Analysis
    • Discriminates between groups
    • Predicts group membership
    • NPAR option (non parametric test)
  • Discriminant Analysis Code
    • PROC DISCRIM
      • PRIORS
      • CLASS
      • CROSSVALIDATE
    • LIST
    • SHORT
    • POOL = YES
    • METHOD=NORMAL or METHOD=NPAR
    • OPTIONS:
  • Discriminant Analysis-Selection of Significant Variables
    • Variables that differ between groups
    • PROC STEPDISC
    • METHOD=STEPWISE
    • SLE = 0.4
    • SLS = 0.05
    • PROC STEPDISC DATA=‘ name of file’ METHOD=STEPWISE SLE=0.4 SLS=0.05;
    • *SLE(S)=SIGNIFICANCE LEVEL OF ENTRY INTO STEPWISE CANONICAL CORRELATION;
    • CLASS VIRTRAD;
    • VAR country size lengthexist explifespan group survey teambuild comfrtgroup satwork cohesiv ;
    • TITLE2 'STEPWISE DISCRIMINANT ANALYSIS OF VIRTUAL TEAMS DATA';
    • RUN;
  • Study Conclusions
    • Number of countries spanned by the team
    • Industry/Type of organization
    • Member satisfaction with working conditions
    • Member comfort level with group interactions
    • Group cohesiveness
  • Methodology Summary
    • 2. Reliability
    • Survey Development
    4. Validity Task Step SAS Tool PROC CORR, ALPHA 3. Data Reduction PROC FACTOR PROC DISCRIM PROC LOGISTIC
  • Thank you
  •