Final Exam Flashcards
One-Way ANOVA: Testwise Type 1 Error Rate
α = .05
- 1 t-test
One-Way ANOVA: Experimentwise Type I error
rate
α ≤ k(k-1)/2
α = .15
- 3 t-tests
Relationship between mean
differences and variance
Use variance to define and measure the size of
the differences among the sample means
Logic of ANOVA
Partitioning variance into
between groups and within
groups (error) variance
Sources of between groups
variance
Sources of within groups
(error) variance
F-ratio under the null and
alternative hypotheses
Distribution of F-ratios under
the null hypothesis
ANOVA summary table and
knowing the relationships
between each value in the table
and the other values
The lower the degrees of freedom, the larger the value of F needed to be significant.
Effect size estimates
- Eta-squared
Multiple Comparison Procedures
- LSD vs. Bonferroni
Assumptions
Why include multiple IVs?
Factorial designs
Factors & levels
If Factor A has 3 levels and Factor B has 5 levels
then there are 3 x 5 combinations in a fully
crossed, factorial design.
– “3 by 5 factorial design”
Sources of variation in
factorial designs
Marginal means
the marginal means of one variable are the means for that variable averaged across every level of the other variable
Decomposing the total
variability
Additivity vs. interactivity
ANOVA summary table
Visually interpreting main
effects and interactions
Effect Size