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COGNITIVE PSYCHOLOGY
PRACTICAL INVESTIGATION
Aim: to investigate recall of acoustically similar and dissimilar words in STM
Experimental hypothesis: whether acoustically dissimilar words more easily recalled by
STM than acoustically similar words, by providing a list of similar and dissimilar words to
participants. (directional)
Null hypothesis: Acoustically similar and dissimilar words will be remembered equally,
no difference.
IV: Changing whether the 10 words on the list are acoustically similar or dissimilar.
DV: how many of the 10 words each participant remembers after 10 seconds.
Control: noise levels of room: distractions affect STM ability =less valid results
Lab experiment:
- High control: minimise extraneous + confounding variables
- Standardised procedure + instructions: easy to replicate
- Contrived situation: pps’ bhv not natural
- Demand characteristics + researcher bias: reduce validity
Opportunity sampling:
- Whole target population can’t be reached
- Convenient: little prep
- Biased: small part of target population
- Available pps refuse to participate = volunteer
Repeated measures design:
- Good control of ppt variables: same pp tested 2x
31
COGNITIVE PSYCHOLOGY
PRACTICAL INVESTIGATION
Aim: to investigate recall of acoustically similar and dissimilar words in STM
Experimental hypothesis: whether acoustically dissimilar words more easily recalled by
STM than acoustically similar words, by providing a list of similar and dissimilar words to
participants. (directional)
Null hypothesis: Acoustically similar and dissimilar words will be remembered equally,
no difference.
IV: Changing whether the 10 words on the list are acoustically similar or dissimilar.
DV: how many of the 10 words each participant remembers after 10 seconds.
Control: noise levels of room: distractions affect STM ability =less valid results
Lab experiment:
- High control: minimise extraneous + confounding variables
- Standardised procedure + instructions: easy to replicate
- Contrived situation: pps’ bhv not natural
- Demand characteristics + researcher bias: reduce validity
Opportunity sampling:
- Whole target population can’t be reached
- Convenient: little prep
- Biased: small part of target population
- Available pps refuse to participate = volunteer
Repeated measures design:
- Good control of ppt variables: same pp tested 2x
31
