Week 9 _Group Differences - Within Groups ANOVA Flashcards
What are the adjusted degrees of freedom when the assumption of sphericity has been violated?
Adjusted df= Epsilon x (k - 1)
Can also be expressed as Epsilon x Sphericity assumed degrees of freedom
What kind of planned comparisons are best used to determine changes over time?
Orthogonal Polynomial Planned Comparisons
What is linear change over time?
Change that occurs at a constant increase/decrease over time
What is a non-linear change over time?
Change over time that is not constant
What is a first order polynomial?
Linear Effect
What is a second order polynomial?
Quadratic effect
What is a third order polynomial?
Cubic Effect
What is a fourth order polynomial?
Quartic Effect
How many polynomial order numbers will there be for a set of planned comparisons?
k-1
What is the advantage of using orthogonal polynomial contrast weights?
SS occasions is completely accounted by the model.
When calculating standardised mean contrasts, what value must be assigned to the contrast weights?
The positive values must = +1 and the negative values must = -1.
XCEI will automatically do this, but need to remember when doing hand calculations.
What are the two kinds of standardised mean contrasts for within-subjects design?
- Standardised Group Differences
2. Standardised Individual Change
What are Standardised Group Differences analogous to (from dependent samples t-test)?
Dunlaps d and Bonett’s delta
What are Standardised Individual Differences analogous to (from dependent samples t-test)?
Hedges g
Why are Standardised Group Differences reported when we are interested in Individual Change?
Because CI estimates can only be obtained from Standardised Group Diffs (point estimate only available for Individual Diffs).
