what is between subjects design
different subjects in each condition
no repeated measures
all observations are conceptually independent of all other observations
what are the assumptions of a two way between subjects ANOVA (same as one way between subjects ANOVA)
sampling distributions of cell means are normally distributed
homogeneity of variance: variability within various cells are equal, or if not, the cell sizes are equal or nearly equal
how to tell if there is an interaction effect without looking at output
on a graph, the two lines will be slightly different
if lines are parallel, there is no interaction
what are residuals
portion of data variation not explained by factors or interaction