AQA Psychology (A-Level) - Research Methods - Experimental Designs Questions and Answers 100% Accurate

Experimental design - ANSWER -A set of procedures used to control the influence of factors such as participant variables in an experiment. Matched pairs design - ANSWER -Pairs of participants are matched in terms of key variables. Each member is allocated to a different group (experimental or control). Advantage of an MPD - ANSWER -The researchers have control, to SOME extent, over participant variables. Advantage of an MPD - ANSWER -The results of this experimental design are the most valid compared to the other two. Disadvantage of an MPD - ANSWER -Very time-consuming and difficult to match participants on key variables, as the researcher has to start with a large group of participants to ensure they can obtain matched pairs on a key variable. Disadvantage of an MPD - ANSWER -It is not possible to control ALL participant variables, as you can only match on variables known to be relevant, but it could be that others are more important. (You may match on memory abilities in a memory experiment, then find some participants had taken a teaching programme to boost memory skills and the researcher should have matched on this). Independent groups design - ANSWER -Participants are allocated to two or more groups representing different levels of the IV. Advantage of an IGD - ANSWER -There are less chances of demand characteristics developing. Advantage of an IGD - ANSWER -There will be NO order effect. Disadvantage of an IGD - ANSWER -The researcher cannot control the effects of participant variables; e.g. Group A participants having better memories than Group B's - an example of a confounding variable.