What is random sampling?
Random sampling is the ‘lottery method’, every person in the target population had an equal chance of being studied.
What are the strengths of random sampling?
•Less chance of researcher bias
•Increased generalisability
What are the limitations of random sampling?
•Doesn’t guarantee that it’s representative
•Bias, certain groups may be over/ under represented
•Likely to need a large sample
What is snowball sampling?
Getting one participant and using their contacts in similar situations to participate.
What are the strengths of snowball sampling?
•Effective for hard to reach groups
•P’s are more likely to take part
What are the limitations of snowball sampling?
•No way of knowing if the sample is representative of the population
•High risk of sampling bias
What is self-selected sampling?
Participants volunteer to take part in the study.
An advert would be placed in an appropriate place.
What are the strengths of self-selected sampling?
•can target specific groups
•researchers get informed consent
•If socially sensitive, p’s can opt in or out easily
What are the limitations of self-selected sampling?
•likely to be bias
•less able to generalise research to the rest of the population
What is opportunity sampling?
Using anyone who happens to be there at the time to be participants.
What are the strengths of opportunity sampling?
•quick and easy sampling
•cost effective
What are the limitations of opportunity sampling?
•Most chance of being sampling bias
•Potential of sampling bias
•less able to generalise research
That categories are under ‘respect’?
•Informed consent
•Right to withdraw
•Confidentiality
What categories are under ‘responsibility’?
•Protection of the participant - no physical or psychological damage
•Debrief - p’s should have the full details of what you intend to do
What categories are under ‘integrity’?
•Deception
Why is competence important?
It is important that psychologists work with their own capabilities, they should also get checked by peers.
