Factorial Design Flashcards

Flashcards covering the key concepts of factorial designs, including experimental design names, ANOVA, and simple main effects.

What is a factorial design?

A design including multiple independent variables.

What is the name of an experimental design with one independent variable?

One-way design.

What is the name of an experimental design with two independent variables?

Two-way design.

What is the name of an experimental design with three independent variables?

Three-way design.

What are the types of independent variables used in experimental design?

Between-groups, within-subjects, or mixed design.

What do we want to know in a factorial design?

The effects of each individual variable (main effect) and the effects of two or more variables when considered together (interaction effect).

What are the stages of two-way between-groups ANOVA?

State the null hypothesis, Partition the variability, Calculate mean squares, Calculate F-ratios.

What are the three null hypotheses in a two-way ANOVA?

Means of different levels of IV A are the same; Means of different levels of IV B are the same; Difference between means of B are different at different levels of A (there is no interaction).

What components make up the partitioning of variability in a factorial design?

Total Variability (SST), Variability explained by the experiment (SSM), Variability explained by Variable A (SSA), Variability explained by Variable B (SSB), Variability explained by an AxB interaction (SSAxB), Unexplained variability (SSR).

What is the Total Sum of Squares (SST)?

Variability of all scores in a dataset (regardless of group assignment).

How is SSM calculated?

Σ (−)2

How are SSA and SSB calculated?

Σ (−)2 and Σ (−)2

How do you calculate mean squares for main effects, interactions, and error term?

= where = −1, = where = −1, = where = ( −1)( −1), = where = Σ(−1 )

How do you calculate F ratios for main effects and interactions?

By dividing their mean squares by our mean square error.

What are simple main effects?

An analysis comparing the effects of one independent variable at different levels of the second independent variable.

What should you do when there is a significant interaction between factors?

Follow up results with a simple main effects analysis.