Experimental designs. Flashcards
WHAT IS INDEPENDENT MEASURES?
Ps are placed in different conditions e.g. half perform in silence half perform with music playing.
2 STRENGTHS OF INDEPENDENT MEASURES?
Be quicker for ps to carry out then repeated measures so recruiting ps may be easier.
Ps may be less likely to guess the aim of the study so less demand characteristics than repeated measures.
2 WEAKNESSES OF INDEPENDENT MEASURES?
Hard to keep all variables constant across all conditions.
There will always be uncontrolled p variables which may confound results and reduce validity.
WHAT IS REPEATED MEASURES?
Each p is tested in both conditions.
2 STRENGTHS OF REPEATED MEASURES?
Same ps in each condition so no participant variables effect the results so higher validity.
Simple strategies are used like counter balancing can be used to control for possible order effects.
2 WEAKNESSES OF REPEATED MEASURES?
Ps may suffer from boredom or fatigue or become practised at the tasks therefore order effects are displayed.
Ps are more likely to guess the hypothesis therefore results may be effected by demand characteristics.
WHAT IS MATCHED PAIRS?
All ps are prescreened on any variables that might effect their performance on their task and matched in pairs across the two conditions.
2 STRENGTHS OF MATCHED PAIRS?
Reduces the effects of key p variables.
No order effects therefore validity will be higher.
2 WEAKNESSES OF MATCHED PAIRS?
Practically difficult to do, takes time, meaning fewer ps may be tested, unrepresentative sample.
Requires twice as many ps as one of the other designs so may be harder to obtain sample.
