Experimental Design Flashcards
What are the 3 experimental designs
Independent group design
Repeated measures design
Matched pairs design
Independent group design
Participants are allocated to different groups where each group represents one experimental condition
Independent group design strengths
+ Order effects aren’t a problem
+ Participants are less likely to guess aim
Independent group design weaknesses
- Confounding variables may occur
- Decreases validity
- Less economical
Repeated measures design
All participants take part in all conditions of the experiment
Repeated measures design strengths
+ Participant variables are controlled
+ Higher validity
+ Fewer participants needed
Repeated measures design weaknesses
- Order effects
- Boredom or fatigue from doing both conditions
- Demand characteristics
Matched pairs design
Pairs of participants are first matched ion some variables that may affect the dependant variable (Condition A and B)
Matched pairs design strengths
+ order effects and demand characteristics are less of a problem
+ reduced participant variables
Matched pairs design weaknesses
- Matching the pairs may be time consuming and expensive
- Less economical
Random Allocation
An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being selected in one condition as any other
Counterbalancing
An attempt to control for defects order in a repeated measures design: half the participants experience of conditions in one order and the other half in the opposite order
