Factorial Designs Flashcards
(14 cards)
What are factorial designs?
Designs which include multiple independent variables.
What is the name of an experimental design with one IV? Two IVs? Three IVs?
One-way design.
Two-way design.
Three-way design.
What is a 2x3 experimental design?
When the first IV has two levels and a second IV has three levels.
E.g., coffee X time of day
- Factor coffee has two levels: cup of coffee or cup of water.
- Factor time of day has three levels: morning, afternoon, and evening.
What is a 3x2x4 experimental design?
When there are multiple IVs with multiple levels each.
E.g., coffee X time of day X exam duration
Factor coffee has three levels: 1 cup, 2 cups, 3 cups
Factor time of day has two levels: morning or evening
Factor exam duration has 4 levels: 30min, 60min, 90min, 120min
What is a mixed design?
If at least one IV is between-groups and at least one IV is within-groups.
What is the effect of a single variable known as?
Main effect
What is the effect of two variables considered together known as?
Interaction effect
For two-way between-groups design, an omnibus F-ratio is calculated for what 3 things?
- Main effect of the first variable
- Main effect of the second variable
- Interaction between the first and second variables
What are the 4 steps of analysing a two-way between-groups design?
- State the null hypotheses (𝐻_0)
- Partition the variability
- Calculate the mean squares
- Calculate the F-ratios
How many null hypotheses are there for a two-way between-groups design?
3.
What refers to the residual error? What is this?
S/AB. This is what’s left over when we’ve accounted for A.
What is the F-ratio for the main effect of A?
MSA / residual error.
What is the F-ratio for the main effect of B?
MSB / residual error.
What is the F-ratio for the main effect?
MSAB / residual error.
