Module 1 Flashcards
Define interactions:
Where a particular effect or relationship between variables changes as a function of another variable (e.g. when the effect of an IV on a DV changes as a function of a second IV)
How do interactions add nuance to established effects?
They indicate the conditions under which the effect is likely to be stronger, weaker, non-existent, or even reversed (e.g. boundary conditions)
Define factor:
Another term for independent variable in the context of ANOVA
Define levels:
Another term for the conditions or groups of the factor
When are one-way ANOVA’s used ?
When we are interested in the effect of one factor on a dependant variable
When do we use factorial ANOVA’s?
When we are interested in the effect of two or more factors on a DV, as it allows us to examine the effects of two or more factors simultaneously.
What does a factorial design have:
- At least two factors
- Each with at least two levels
What types of effects foes a two-way factorial ANOVA produce?
- Main effect of factor A
- Main effect of factor B
- Factor A x Factor B interaction (does the effect of factor a on the dv change at each level of factor b)
Define the grand mean:
The mean of all observed scores
Define marginal means:
The average of all scores on each level of one factor, collapsing over levels of the other factor(s).
Define cell means:
The average of all scores at each level of one factor, at each level of the other factor(s).
When spotting a potential interaction, what would parallel lines suggest?
There is no interaction
When spotting a potential interaction, what would non-parallel lines suggest?
There may be an interaction
When spotting a potential interaction, what would the lines crossing suggest?
A disordinal interaction
When spotting a potential interaction, what would lines that do not cross, but are not parallel suggest?
Ordinal interaction
Define variable:
Anything that can vary
Define variance
A measure of the dispersion or spread of scores around a point of central tendency
Why is the grand mean included in hypotheses?
If there are no differences across the group means (if the null hypothesis is true), all of the means will sit on the grand mean.
Define between-groups variance
Systematic variation in DV between the different groups/levels/treatments of the IV (treatment variance)
Define within-groups variance
Random variation in DV within the groups that can’t be explained by the IV; due to unmeasured influences (error variance)
What is a factorial between-participants ANOVA?
A statistical method used to analyze the effects of two or more independent variables on a dependent variable across different groups.
What are the key components of a factorial design?
- Independent Variables (IVs)
- Dependent Variable (DV)
- Levels of each IV