Chapter 12 - Factorial Designs Flashcards
define interaction effect
where the difference in levels of one IV changes, depending on the level of the other IV, a difference in differences
when looking at tabular data, the averages for all the IVs would be the same so you can say that because of this moderotr, it is causing the change. would produce an X if it was graphed
define factorial design
a study where there are two or more IV, can have both interaction and main effects
define cell
a condition in an experiment, in factorial, it represent one of the possible combos of the 2 IV
define participation variables
a variable such as age, gender or ethnicity whose levels are selected, not manipulated
define main effect
the overall effect of 1 IV on the DV, averaging over the levels of the other IV
when looking at a table of means, when looking at one variable, and seeing that there is a difference in averages, means that there is a main effect
define marginal means
arithmetic means for each level of an IV, averaging over the levels of another IV
explain what ta 2x2 factorial design is>
each number indicates the number of levels of each independent variables, when combining this gives all the possible conditions in the experiment
what are teh different kinds of interactions?
crossover: effect of 1 IV on DV is positive at one level of the 2nd IV but negative at another levels on the 2nd IV, complete reverse effect
spreading: effect of IV 1 on DV is stronger at one level of IV2 than at another level, strength differ depends on other IV
what does it mean when lines on a graph run parallel to each other?
that there is no interaction
define independent roups factorial
bothd IVs are manipulated as independent groups, each condition needs a whole new set of people
define within groups factorial?
both IVs are manipulated as within groups. same people doing all the condition, want the people to be as similaire as possible so you can cancel all those other variables out of the pictures but hard to do
define mixed factorial
one IV is manipulaed as independent and the other IV is manipulated as within. Groups of people are shown one condition of one IV and both of the other.
how many main effects are possible in a study?
you can have main effect for how ever many IVs there are
hwo many interactions are possible in a study?
can have as many as you have variables that will interact with each other
