What makes a factorial design?
Designs that have at least two IVs are known as factorial designs
Designs that have at less than two IVs are known as factorial designs
What can factorial designs assess?
Main effects and Interaction
Main interactions and Simple effects
Marginal Means and simple means
Interaction
What are the advantages of a Factorial Design?
Less time consuming, effective, ethical
require fewer participants, can examine interactions between IV's, can generalise results
An interaction occurs when:
One IV interacts with another IV when the effects of one IV are different depending on which level of the other IV is being considered and One IV interacts with another IV when it changes the impact of another IV on the DV
One Iv has an interaction with another level and DV shows responses on different levels
Does the "Grand Means" equate to the means of all the observations?
Are Marginal Means calculated for each factor or just for the factor which is being examined?
Each Factor
Examined Factor
Cell means are the simple effects that are investigated at the level of cell means.
What is the function of simple effects?
As a follow up test.
To compare means
To follow up and interpret a significant interaction.
What are the Assumptions for Factorial Design?
Normality
Homogeneity of Variance
Independence of sample Variance
Independent of Random Sampling
DV scores have to be the same
All of the Above
Factorial experiments allow researchers to:
Combine each treatment’s main effects to see the overall effect they have in a study
Contrast the average of these main effects to determine if the treatment has one effect on one group of participants and another effect on another group of participants
A and B.
Main effect is isolating one factor and examining the effect of this factor on the DV
In Factorial designs, you compare one treatment’s main effects with another treatment’s main effects and if one factor differs significantly at discrete levels of the other factor we have an interaction.
Can Interactions be both ordinal and disordinal?
For each pair of factors there are two main effects and one interaction which can occur in any combination. Which one is most correct?
Two Main effects but no interaction
Interaction but no main effect
One main effect only
One main effect & an interaction
All of the above.
