what is groupmatching and counterbalancing, in refererence to psychology?

Answer 1

there are methods for reducing the random error that is associated with psychological research.
in group matching, you match subjects based on certain background characteristics that would others be confounding (e.g. socio-economic status, educational attainment, race, nationality, etc.). An example would be if you were testing the effects of a diet drug and you matched subjects that have similar background variables to measure the "truer" effect of the diet drug.

counterbalancing is a method used to ensure that subjects get "equal treatment" in the experiment. For example, if you are running a survey, you have to switch around the order of the questions in order to avoid any survey effects. To counterbalance this design you would make sure subjects get different permutations of the order of the question (i.e. 10 subjects will answer questions in order: 1,2,3 .10 subjects will answer in order: 2,3,1, 10 subjects will answer in order :3,2,1.. etc etc.

Answer 2

Methods for ensuring that comparison groups in a study begin equivalent with respect to certain specific variables.

Answer 3

Yes if carried out and thought out properly. Not all the time though it depends on how fixed the victim of the reverse psychology is on their decision