Chapter TwelveB: Comparing Groups Analysis of Variance

1
Chapter Twelve(B) Comparing Groups Analysis
of Variance

• DBA 903
• Research Methods III
• J. Schreiber

2
ANOVA and Regression

• ANOVA is a special case of regression
• Set up dummy variables
• Only one can be nonzero
• Need __ dummy variables for n groups
• Can then solve for mean estimates through
  functions of the betas

3
Two-way ANOVA Regression

• Sum of squares for a factor describes
  __________________________________________________
  ____________________
• Mean square error
• Equals_______________________________
• Estimates ____________________________
• Null hypotheses are tested by_____________________
  ___________

4
Partial Sums of Squares

• These will add up to the model sum of squares
  when ________________________
• This ______ happens in experimental designs and
  ______ happens with survey research
• When there is no significant evidence of
  interaction, we should _________________ before
  forming confidence intervals and conducting
  inference

5
Multiple comparisons in two-way ANOVA

• No interaction
• Interaction

6
Factorial ANOVA

• Factors
• Factorial ANOVA

7
Repeated measures

• Fixed effects
• Random effects
• Mixed model

8
Repeated measures (cont.)

• Within-subjects factor
• Between-subjects factor
• Crossed
• Nested