the different ways in which participants can be organised in relation to the experimental conditions
what is the memory aid for experimental design
r - repeated measures
I - independent groups
m - matched pairs
what is repeated measures
all participants take part in all conditions of the experiment
what is independent groups design
participants are allocated to different groups where each group represents one experimental condition
what is matched pairs
pairs of participants are first matched on some variables that may affect the dv. one member of each pair does one conditions + the other does another through random allocation
what is random allocation
an attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other
what is counterbalancing
an attempt to control for the effects of order in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order
