Experimental methods and designs Flashcards
(17 cards)
extraneous variables
variables that make it difficult to detect an effect (weather, sleep)
confounding variables
variables that change with the IV (age)
demand characteristics
anything that reveals the purpose of a study, changing the participants behaviour
investigator effects
any effect of a researchers behaviour on the outcome of the research
randomisation
the use of chance when designing investigations to control for the effects of a bias
standardisation
using the same procedures for all pps in a study or the differences become EVs
pilot studies
trial run of an investigation to test procedures to see if design needs to be modified
control groups
groups used as a baseline in control conditions
single blind
pp doesn’t know the aims of the study - reduced demand characteristics
double blind
both pp and investigator dont know aims to reduce demand characteristics and investigator effects
3 types of experimental design
independent groups
repeated measures
matched pairs
independent groups
pps randomly allocated to 2 groups and have 2 separate conditions
+/- independent groups
no order effects
no guess aim / demand characteristics
pp variables
less economical
repeated measures
same pps take part in all conditions
order of conditions should be counterbalanced to avoid order effects
+/- repeated measures
pp variables
fewer pps
order effects - knowledge/fatigue
guess aims/ demand characteristics
matched pairs
two groups used for different conditions but pps are related through participant variables
+/- matched pairs
no order effect
pp variables matched
matching is not perfect
more pps
