MAVOVA Flashcards
what is a manova?
An anova with multiple DVs
Multivariate analysis of variance
What is the DV in manova?
2 or more DVs are all measures of the same construct (e.g. 3 memory tests)
Linear composite (LC) is the linear combination of multiple DVs
Different combination of DV for each effect in the design
When can manova be used?
Same as anova:
repeated-measures, between-groups, factorial designs (more than 1 IV). can include covariates (MANCOVA)
Central question in manova
Are there mean differences between groups on a combination of DVs?
manova and DA (discriminant (function) analysis)
Mathematically the same
manova is DA in reverse
manova- compare 2 or more groups on mulitple DVs
DA- same data, but use linear composites to PREDICT group membership
Why include multiple DVs?
Capture broader and richer information
Good IVs might effect DV in more than one way, so include several DVs
e.g. stress intervention (IV) might cases changes in different variables (the DVS- physiological, emotional, observational responses)
What does manova inferentially identify?
1) different levels of the IV have a significant effect on a liner combination of DVs
2) there are interactions between IVs and the LC
3) WHERE the effect is- are there significant univariate effects for each of the DVs?
When does manova work well?
manova works well when there is MODERATE correlation between DVs
Too high (>.8)= not enough variance left after the first DV
Too low (
Linear composites (LCs)
A linear combination of the DVs
Different to univariate approach where for 3 DVs, there would be 3 separate anovas
LCs in a factorial design
Different LCs are created for each main effect and interaction, same with comparisons
mavova F statistic
If the manova F statistic is significant, LC differs as a function the IV
:( difference in the LC could be due to IV differences among any, or all of, the DVs- it doesn’t tell you where the differences lie
How are DVs combined in the LC?
DVs are combined to separate the groups as much as possible
