sampling methods

Question 1

what are the 4 sampling methods

Answer 1

random
stratified
volunteer
opportunity

Question 2

what is random sampling

Answer 2

placed into a system that would enable members of target population to be picked with equal chance of being selected

Question 3

what are the strengths of random sampling

Answer 3

+ for large samples it provides the best chance of unbiased representative samples due to equal chance
+ clear to everyone how sample is being chosen

Question 4

what are the weaknesses of random sampling

Answer 4

• time consuming to make list of everyone, not everyone may be available causing bias
• can still be bias even though equal chance

Question 5

what is stratiffied sampling

Answer 5

divide target population into sub categories in proportion to subgroup frequency

Question 6

what are the strengths of stratified sampling

Answer 6

+ each group is represented so conclusions can be drawn
+ limits numbers of pts needed to be representative

Question 7

what are the weaknesses of stratified sampling

Answer 7

• difficult to know how many of each group to choose to make findings generalisable
• time consuming for proportions to be calculated

Question 8

what is volunteer sampling

Answer 8

advertise research for people to respond to, to take part in research and become participants

Question 9

what are the strengths of volunteer sampling

Answer 9

+ pts intrested and less likely to gived biased info, demand characteristics and social desirability reduced
+ more ethical than other methods as pts come to researcher

Question 10

what are the weaknesses of volunteer sampling

Answer 10

• unrepresentative as it leads to bias on the part of the participant
• sample bias, pts highly motivated, take time for volunteers to apply

Question 11

what is opportunity sampling

Answer 11

selecting people avaliable at time and in location of research

Question 12

what are the strengths of opportunity sampling

Answer 12

+ more quick covenient and economical than other methods, research has control
+ more ethical, research can judge if pts are going to be upset or busy

Question 13

what are the weaknesses of opportunity sampling

Answer 13

• very unrepresentative researcher mre likely to chose ‘helpful’ pts, small subgroups of target population
• researcher bias, ask certain types of people to take part