Experimental designs Flashcards
What are the four experimental designs?
- Independent groups
- Repeated measures
- Matched pairs
What is an independent groups design?
- when two seperate groups of participants experience two different conditions of an experiment
- this means all participants only see one level of IV
What are the strengths and weaknesses of independent group designs?
Strengths: No order effects and less demand characterisrics
Weakness:
- No control over participant variables, as the participants are different and may have different abilities that can change the DV. This increases the amount of confounding variables
- less economical
What is repeated measures?
- All participants experience both conditions and all levels of the IV
Evaluate repeated measures
Strengths = participant variables are very controlled and fewer participants are needed
Limitations = Order effetcs such as boredom and fatigue can act as confounding variables
What is matched pairs design?
- Participants are paired together based on a variable that can affect DV
- each member expierences one level of the IV
Evaluate matched pairs design
Strengths = No order effects and less demands characteristics
Weakness = Time consuming and expensive to match participants
- A large number participants are required
- there still may be important differences between participants
What are the solutions to the weaknesses of independent groups design and repeated measures
- Independent group design = random allocation
- Repeated measures = counterbalancing
what is counterbalancing?
- an attempt to solve the weaknesses of repeated mesures where one half of participants expierence the conditions in one order and the other half expierence it in another
what is random allocation
- every participant has an equal chance of being in a condition
