Sampling

Question 1

what is a random sample

Answer 1

• all members of the target population have an equal chance of being selected
• obtain a list of all members
• names on list assigned a number
• use a random number generator

Question 2

what is the evaluation of random sampling

Answer 2

• potentially unbiased
• difficult
• time consuming
• sample may be unrepresentative
• selected pps may refuse to take part

Question 3

what is systematic sampling

Answer 3

• every nth member of the target population is selected
• sampling frame = list of people in the target population organised

Question 4

what is the evaluation of systematic sampling

Answer 4

• objective method
• once system is selected the researcher has no influence over who is chosen
• time consuming method
• pps may refuse to take part

Question 5

what is stratified sampling

Answer 5

• composition of the sample reflects the proportions of people in sub groups
• researcher identifies different strata that make up the population
• proportions needed for the sample to be representative are worked out

Question 6

what is the evaluation of stratified sampling

Answer 6

• produce representative sample
• reflects composition of the sample
• generalisation is easier
• identified strata cannot reflect all the ways people are different

Question 7

what is opportunity sampling

Answer 7

• select anyone who is willing

Question 8

what is the evaluation of opportunity sampling

Answer 8

• convenient and less costly
• unrepresentative of population
• findings cannot be generalised
• researcher bias

Question 9

what is a volunteer sample

Answer 9

• pps select themselves to be part of the sample

Question 10

what is the evaluation of volunteer sampling

Answer 10

• easy to obtain
• requires minimal input
• volunteer bias
• attracts a ‘profile’ of someone