Sampling

Question 1

what is the difference between a population and a sample

Answer 1

The population is the group of individuals that the researcher is interested in and from whom the sample is drawn

The sample is the representative subset of the population being studied

Question 2

list the different sampling techniques

Answer 2

1) randomised sampling
2) opportunity sampling
3) stratified sampling
4) systematic sampling
5) volunteer sampling

Question 3

why is a sample used

Answer 3

Researchers cant physically study all individuals in a population. A sample is used to be a smaller representative subset of the population from which researchers can draw conclusions from and generalise it across to the wider population

Question 4

What is opportunity sampling

Answer 4

a sample of pps produced by selecting individuals who are available at the time of the study

Question 5

Evaluate opportunity sampling

Answer 5

+ the easiest method of sampling as you just use who is there at the time, this is quick and efficient
- Bias sample= everyone is drawn from the same small part of the population, this creates an unrepresentative sample

Question 6

what is randomised sampling

Answer 6

a sample of pps produced using randomised techniques so that everyone in the target population has an equal chance of being selected

Question 7

Evaluate random sampling

Answer 7

+ unbiased as everyone has an equal chance of being selected

• may take time as everyone’s names need to be listed, selected, and then contacted

Question 8

what is a stratified sample

Answer 8

a sample of pps produced by identifying subgroups based on their frequency within the entire population. Pps are selected randomly from those subgroups

Question 9

Evaluate stratified sampling

Answer 9

+ the most representative due to a proportional and randomly selected pps

• time consuming to identify subgroups and randomly select them

Question 10

what is systematic sampling

Answer 10

a sampling technique of pps by selecting every nth person in a list

Question 11

evaluate systematic sampling

Answer 11

+ unbiased as pps selected using an objective system

• not truly unbiased or random unless using a random number system, start with that person, then do every nth person

Question 12

what is volunteer sampling

Answer 12

a sample of pps that relies solely on volunteers to make up the sample
aka a self selected sample

Question 13

Evaluate volunteer sampling

Answer 13

+ provides a variety of pps which may make the sample more representative and less bias

• sample may still be biased as sample are likely to be highly motivated and have more time on their hands creating volunteer bias

Question 14

Define bias

Answer 14

a systematic distortion