6) sampling methods key terms

Question 1

What is the target population?

Answer 1

The groups the researcher wants to study

Question 2

Why is a target population used?

Answer 2

Because the researcher can’t have everyone, so they select a smaller group

Question 3

What is a sample?

Answer 3

A small group of people who represent the target population in the study

Question 4

What is a key limitation of a sample?

Answer 4

It may be biased as it consists of only those available at the time

Question 5

What does sampling enable us to do?

Answer 5

If its representative, you can generalise the results of the study to the wider population

Question 6

What are the 6 sampling techniques?

Answer 6

-random sampling
-opportunity sampling
-volunteer sampling
-systematic sampling
-stratified sampling

Question 7

What is random sampling?

Answer 7

Every member of the target population has an equal chance of being chosen

Question 8

What is a sampling frame?

Answer 8

A complete list of all members of the target population

Question 9

How are participants selected from a sampling frame?

Answer 9

A computer-based randomiser or pull names from a hat (lottery method)

Question 10

What are the pros of random sampling?

Answer 10

-no bias
-everyone has an equal chance to be picked
-sample is more likely to be representative

Question 11

What are the cons of random sampling?

Answer 11

-impractical
-more time and effort needed
-not completely representative

Question 12

What is opportunity sampling?

Answer 12

A technique that involves recruiting anyone who happens to be available at the time of the study

Question 13

How is opportunity sampling conducted?

Answer 13

Researcher goes out where they are likely to find their target population and ask people to take part

Question 14

What are the pros of opportunity sampling?

Answer 14

-simple
-quick
-easy
-cheap
-naturalistic (natural environment)

Question 15

What are the cons of opportunity sampling?

Answer 15

-unrepresentative
-cannot confidently generalise

Question 16

What is volunteer sampling?

Answer 16

When people actively volunteer to be in the study by responding to a request advertised by the researcher (self-selecting)

Question 17

How is volunteer sampling conducted?

Answer 17

-People sign up to take part on a request advertised
-Researcher only selects people who are deemed suitable

Question 18

What are the pros of volunteer sampling?

Answer 18

-convenient
-economical
-wide audience

Question 19

What are the cons of volunteer sampling?

Answer 19

-sampling bias
-don’t know who the people are (online they might be lying)

Question 20

What is systematic sampling?

Answer 20

Involves selecting names from a sampling frame in regular intervals

Question 21

How is systematic sampling conducted?

Answer 21

-sampling frame is produced
-sampling system is nominated (e.g. every 7th person pulled is being used)
-researcher works through the sampling frame until the sample is complete

Question 22

What the pros of systematic sampling?

Answer 22

-simple to conduct
-objective system
-reduces researcher bias

Question 23

What are the cons of systematic sampling?

Answer 23

-not truly unbiased
-representativeness is not guaranteed

Question 24

What is stratified sampling?

Answer 24

Participants are selected from different subgroups (strata) in the target population in the same ratio as they are subgroups in the population
(E.g. if 10% of the strata are age 10-12, then 10% of those used should be age 10-12)

Question 25

How is stratified sampling conducted?

Answer 25

-Identify the number of participants in each strata
-Work out the % of each strata to make up the target population
-researcher then uses random sampling to select the sample

Question 26

What are the pros of stratified sampling?

Answer 26

-most representative

Question 27

What are the cons of stratified sampling?

Answer 27

-knowledge of population characteristics are required
-time consuming