Experimental Designs

Cards (9)

Repeated Measures Design 
Participants take part in all conditions.
Advantages of Repeated Measures Design
There are no individual differences between Ps because its the same Ps in each group
Fewer Ps are required, so more economical
Independent Measures Design 
A different set of Ps are used in each of the conditions
Disadvantages of Repeated Measures Design
Order effects can occur where they might do better in a second condition because of practice or are bored (overcome by counterbalancing)
It can not always be used because once you have taken part in one condition you cannot do the other due to learning a technique.
Advantages of Independent Group Design
No order effects of practice or boredom
Most widely used as there is no matching required and no problem of the order.
Disadvantages of Independent Group Design
Individual difference of the Ps in the groups, if might be that you have put together a group with a significantly higher average IQ than the other, so they preform better
Uneconomic use of Ps as you will need more.
Matched Pairs Design 
A different set of Ps are used in each condition of the experiment, they are matched on important criteria, e.g. intelligence
Advantages of Matched Pairs Design 
No order effects
Reduces individual differences as groups are matched on important requirements.
Disadvantages of Matched Pairs Design 
Time consuming to get pairs
Expensive
Exactly matched participants are impossible to achieve