what is a complex experiment?
experiments with more than one IV
what is an interaction?
a difference in differences. the effect of one IV depends on the level of the other IV
crossover interaction
“it depends” interaction. when the graphs of two IV intersect
spreading interaction
“especially when” interaction. When 2 IV initially correlate with each other, then spread apart.
what is a factorial design?
experiment where there are 2+ IVs (factors)
define cells (factorial design)
each unique condition in a factorial design
define participant variable (factorial design)
characteristic of participants that is not manipulated, but rather treated as a factor (i.e. age when comparing young and old drivers – you can’t manipulate age, but you can treat it as a factor in a factorial design)
what is the benefit of factorial design?
testing limits (a form of external validity). interactions can also show moderators.
define moderator (interaction)
IV that changes the relationship between another IV and a DV. the effect of one IV depends on the level of another IV
how to interpret factorial results
main effects and interactions
define main effect
is there an overall difference? the individual effect of a single IV
define interactions
is there a difference in differences? arguably more important than main effects
