Experimental design Flashcards
What have experimental designs?
Only experiments have experimental designs (E.G. lab, field, quasi, natural). There’s 3 main types of experimental designs-
- Repeated measures design
- Independent groups design
- Matches pairs design
What is a repeated measures design?
The same participants take part in ALL conditions of a study (E.G. memory test, same participants x2.
Advantages and disadvantages of repeated measures design?
+ Eliminates individual differences
+ Makes it easier to identify the effects of the IV on the DV
- Order effects may reduce the validity of the study (E.G. patient may improve on the 2nd condition due to practice or becoming bored).
What is counterbalancing and why/where is it used?
It’s where half the participants do condition A first followed by condition B whereas the other half of participants would do condition B followed by condition A.
It can be used to improve the validity of a repeated measures design.
- This offsets any improvement/boredom condition B with equal improvement/boredom in condition A, so minimises order effects.
What is an independent groups design?
Use different participants in different conditions of the study (E.G. 10 would sit memory test w/ music and a different 10 w/ no music. Not matched).
Advantages and disadvantages of independent groups design?
+ No order effects as different participants are taking part in conditions.
+ Improves validity
- Groups of participants haven’t been matched in terms of age, gender etc.
- Individual differences affect results.
- Lowers validity.
What’s matched pairs design?
Uses different participants in conditions. Yet different groups are matched in terms of age, gender etc.
Advantages and disadvantages of matched pairs design?
+ Individual differences wont affect the outcome of the study.
+ Improves validity.
- Time consuming
- Finding the matched pairs can prove difficult and take time
