experimental designs Flashcards
what are the 3 types of experimental design?
independent groups, repeated measures, matched pairs
what is repeated measures?
all participants receive all levels of the IV at separate times
what is a disadvantage of repeated measures?
order effects may affect performance because of the practice effect or the boredom effect
what is a second disadvantage of repeated measures?
participants on the second test may guess the purpose of the experiment so may purposely change behaviour
how do you deal with order effects?
- using two different tests to reduce practice effect
- counterbalancing (ensures each condition is tested first or second in equal amounts
how do you prevent participants from guessing the aims of the study?
a cover story can be created about the purpose of the test
what is independent groups?
participants placed in separate groups and each group does one level of the IV
what is a disadvantage of independent groups?
researcher cant control effects of participant variables (different abilities) which acts as confounding variable
what is a second disadvantage of independent groups?
more participants required needed to get the same amount of data which could be more time consuming and expensive
how do you deal with participant variables?
random allocation of participants to conditions which should distribute the participant variables evenly
what is matched pairs design?
matching participants from two different groups on key characteristics believed to affect DV performance
what is a disadvantage of matched pairs?
time consuming and hard to match participants on key variables which also takes time
what is a second disadvantage of repeated measures?
cant control all participant variables as you can only match on variables relevant to study
how to overcome disadvantages of repeated measures?
- restricted number of variables to match on to make it easier
- conduct pilot study to consider what variables might be important when matching
