Sampling

Question 1

What is Sampling?

Answer 1

• Where a researcher identifies a target population and then recruits a sample that is representative of that target population.

Question 2

What are gatekeepers?

Answer 2

• People you have to go through to get to your target population

Question 3

What is Opportunity Sampling?

Answer 3

• A sample of the population who happen to be available at that time.
• Involves getting ahold of the nearest and most convenient people.
• E.g., friends, family, passers-by.

Question 4

What are the advantages of an opportunity sample?

Answer 4

• Quick and convenient
• Possible large sample
• Can do it over social media, emails, online etc.

Question 5

What are the disadvantages of Opportunity sampling?

Answer 5

• Experimenter bias –> May only pick certain people to be PPs in the study.
• Makes the sample unrepresentative and not generalisable.

Question 6

What is volunteer sampling?

Answer 6

• Members of the population who select themselves
• can be through ads, e.g., on social media
• People volunteer to take part - informed consent.

Question 7

What are the advantages of Volunteer sampling?

Answer 7

• Easy to gain informed consent.

- The experimenter doesn’t know who signs up - there can be no experimenter bias.

Question 8

What are the disadvantages of Volunteer sampling?

Answer 8

• Slow and inconvenient - takes a while to gain a sample from a group of volunteers.
• May be unrepresentative - e.g., people in the general population may have different personality types in comparison to those that were in the sample.

Question 9

What is Random sampling?

Answer 9

• This is where members of the target population are selected without any bias.
• E.g., every nth name, names out of a hat, random generator

Question 10

What are the advantages of random sampling?

Answer 10

• There is no bias at all due to the random nature of selection

Question 11

What are the disadvantages of Random sampling?

Answer 11

• Slow and inconvenient - collating names is quite slow.

- May be unrepresentative of the population as accessing names is difficult.

Question 12

What is Stratified Sampling?

Answer 12

• Where the population is split into different “strata” that is needed in the sample - and then the sample is selected randomly.
• E.g., if there’s 60% males and 40% females in the population, then the sample should consist of 60% males and 40% females.

Question 13

What are the advantages of Stratified Sampling?

Answer 13

• No bias at all as there’s different layers of data and it is highly scientific.
• Representative of the strata used.

Question 14

What are the disadvantages of Stratified sampling?

Answer 14

• Very slow and inconvenient

- May ignore important stratas in the general population - it is difficult to get the right proportions.

Question 15

When is each sampling method best to use?

Answer 15

1. Opportunity –> When the target population is grouped together in a location where you can approach a varied selection of them.
2. Volunteer –> When the target population is likely to read the same materials, visit the same places etc.
3. Random –> When the target population isn’t too large, and you can get ahold of a “master list” of all the members - e.g., a payroll.
4. Stratified –> When you have what you need for random sampling, as well as the topic you’re researching suggesting a small number of very obvious strata – e.g., a strata of gender when studying aggression.