Experimental designs Flashcards
What is an experimental design?
a set of procedures used to control the influence of the participants variables so we can see the clear effect of the IV on the DV
What are the 3 basic experimental designs?
- Independent measures design
- Repeated measures design
- Matched pairs design
What does independent measures consist of?
- uses different participants for each condition
- 2 groups in an experiment for instance boys and girls
One advantage of independent measures when using different P’s in each condition?
No order effects
Weakness of independent measures regarding using different P’s in each condition?
Error resulting from individual differences
Weakness of independent measures regarding cost?
Uneconomic use of P’s since twice and many P’s are needed to obtain the same amount of data
When does independent measures have to be used?
In quasi experiments because the P’s cant be randomly assigned to one condition
What is repeated measures design?
Testing the same individuals over two or more conditions
Advantage of repeated measures regarding testing the same individuals?
differences between individuals are removed
Advantage of repeated measures regarding cost?
Fewer P’s are needed so it would be cheaper and quicker
Weakness of Repeated measures regarding P’s doing all of the conditions?
Order effects such as boredom or fatigue could effect the results
What can be done to reduce the effects of order?
counterbalancing where the 1st P would do the 1st condition 1st and the 2nd P would do the 1st condition 2nd
What is a matched pairs design?
Using different participants for each condition by participant variables are controlled by matching pairs of variables on a key variable such as age , IQ
A weakness in matched pairs regarding time and cost?
Very difficult and time consuming which could therefore cost a lot to undertake
