Used to distribute individual characteristics randomly between groups, overcomes the limitation of independent group in terms of participant variable
Counterbalancing
tempts to control for effects of order in repeated measures design: half the pps experience condition in one order and the other half i the opposite order
Ways to counterbalance:
AB or BA (group 1= A then B, group 2 = B, then A)
AA or BB (A then A again, B then B again with results later compared)
Standardisation
keeping everything the same for all pps so that the investigation is fair. All pps should be subject to the same environment, information and experience
