Sampling

Question 1

what is sampling?

Answer 1

the method used to select participants

Question 2

what is a population?

Answer 2

Group of people that a researcher is interested in. The group of people from who a sample is drawn

Question 3

what is opportunity sampling?

Answer 3

a sample of participants produced by selecting people who are most easily available at the time of the study

Question 4

what are the advantages and disadvantages of opportunity sampling?

Answer 4

• less time consuming
• inevitably biased because the sample is drawn from a small population
  i.e selecting people from the centre of town on Monday morning it would be unlikely to include professional people (at work) or people from rural areas

Question 5

what is systematic sampling?

Answer 5

involves applying a regular system or rule when selecting participants
- selecting every 10th person that walks down a corridor

Question 6

what are the advantages and disadvantages of systematic sampling

Answer 6

• unbiased participants are selected using an objective system

Question 7

what is volunteer sampling?

Answer 7

allows participants to select themselves by responding to an advert or email call for participants

Question 8

what are the advantages and disadvantages of volunteer sampling?

Answer 8

• gives access to a variety of participants which may make the sample more representative/less biased
• The sample is biased in other ways because participants are highly motivated/ or have extra time on their hands or need money
• this leads to volunteer bias

Question 9

what is random sampling?

Answer 9

each participants in a target population has an equal chance of being selected

Question 10

name disadvantages and advantages of random sampling

Answer 10

• unbiased (equal chance of selection)
• need to have a list of all the members of the population and then contact all of those selected, which may take some time

Question 11

what is stratified sampling?

Answer 11

researchers first divide a population into smaller groups, or strata based on shared characteristics of the members than randomly select among these groups to form the final sample
i.e subgroups within a population are identified e.g boys and girls or age groups (12-15)

Question 12

Name a strength of stratified sampling?

Answer 12

more representative than other methods because there is a proportional and randomly selected representation subgroups

• very time consuming to identify subgroups, the randomly select participants and contact them