Experimental Design Flashcards
independent groups design
pps only perform in one condition of the IV
independent: strength
no order effects
reduced likelihood of demand characteristics
independent: weakness
participant variables - can’t establish cause and effect
more pps needed
independent: solution
random allocation - ensures each pp has the same chance of being in one condition as the other
repeated measures design
same pps take part in all conditions of the IV
repeated: strength
no participant variables
fewer pps needed
less time consuming
repeated: weakness
order effects
demand characteristics
repeated: solution
counterbalancing - half pps do conditions in one order, other half do it in an opposite order
matched pairs design
pairs of pps are matched on some variable found to have an effect on the DV, then one member of each pair does one condition and the other does another
matched: strength
no order effects
less demand characteristics
matched: weakness
time consuming + expensive
large sample size needed
matching is difficult
matched: solution
n/a
random allocation method
- match each pp with a number
- put numbers into a random number generator
- get the generator to choose a number
- assign that number to condition one
get the random number generator to repeat the process and assign the number to condition two - repeat until all pps are assigned to a condition
counterbalancing (ABBA) (split-half method)
half the pps test one condition and the other half test the other condition
- prevents order effects
