22. Sampling

Question 1

What is a sample

Answer 1

When we carry out research we need people to take part, these are called the participants.

Question 2

What is a population

Answer 2

The group of ppl from whom the sample is drawn. We use a target population if we want to investigate specific differences

Question 3

What are the 5 types of sampling

Answer 3

• Random sampling
• Volunteer sampling
• Opportunity sampling
• Stratified sampling
• Systematic sampling

Question 4

What is random sampling

Answer 4

• Each person has an equal chance of being selected
• Chosen from a computer random generator or picked out of a hat (old fashioned)

Question 5

Advantages of random sampling

Answer 5

• Unbiased - all members of the target population have an equal chance of selection

Question 6

Disadvantages of random sampling

Answer 6

• The researcher may end up w a biased sample if the sample is too small
• Subgroups of the target population may not be selected, so does not guarantee a representative sample

Question 7

What is volunteer sampling

Answer 7

The researcher advertises the study & ppl who are interested apply to be in the research

Question 8

Advantages of volunteer sampling

Answer 8

• Quick, convenient & ethical if it leads to informed consent
• Large response rate
• Allows more in-depth analysis & accurate results

Question 9

Disadvantages of volunteer sampling

Answer 9

• Sample is biased bc the participants are likely to be more highly motivated (volunteer bias)

Question 10

What is opportunity sampling

Answer 10

Asking ppl who are available at the time to take part in the research

Question 11

Advantages of opportunity sampling

Answer 11

• The easy & fastest method bc you just use the first participants you can find

Question 12

Disadvantages of opportunity sampling

Answer 12

• Biased bc the sample is drawn from a small part the target population
• Unlikely to be representative of a target population

Question 13

What is stratified sampling

Answer 13

• Sample reflects the proportions of ppl in certain sub-groups (strata) within the target population or wider population

Question 14

Advantages of stratified sampling

Answer 14

• More representative than an opportunity sample bc there should be equal representation of subgroups

Question 15

Disadvantages of stratified sampling

Answer 15

• It is time consuming bc all potential participants need to be assessed & categorised
• Some groups within a sample may not be represented if small sample is used

Question 16

What is systematic sampling

Answer 16

Selecting every nth name from a list

Question 17

Advantages of systematic sampling

Answer 17

• It avoids bias as once the researcher has decided what number they have no control over who is being selected

Question 18

Disadvantages of systematic sampling

Answer 18

• It is not completely objective bc the researcher may decide on how ppl are listed before the selection
• There is a small chance of a ‘freak’ sample which would not be representative

Question 19

How to carry out opportunity sampling (smarties)

Answer 19

Select the first (eg. 5) (whatever the sample is) that come out of the box

Question 20

How to carry out random sampling (smarties)

Answer 20

Select (sample size, eg 5) from the box without looking

Question 21

How to carry out systematic sampling (smarties)

Answer 21

Lay out smarties in a row, pick every 5th smart until you have 5

Question 22

How to carry out stratified sampling

Answer 22

1. Define your population & subgroups
2. Separate the population into strata
3. Decide on the sample size for each stratum
4. Randomly sample from each stratum

Question 23

How to carry out volunteer sampling (smarties)

Answer 23

Select (5) smarties that are willing and have volunteered to take part