Sampling

Question 1

Define population

Answer 1

The target group of people being studied (based on age, gender, etc.)

Question 1

Define participant

Answer 1

An individual who is recruited to take part in a psychological study

Question 2

Define sample

Answer 2

The group of participants gathered to take part in the study, who represent the population.

Question 3

Define representative

Answer 3

When the sample’s characteristics closely matches those of the target population.

Question 4

Define generalisation

Answer 4

The extent to which the study’s conclusions can be applied to the broader population.

Question 5

Define bias

Answer 5

When certain groups of the target population are over/under-represented within the sample (for various reasons)

Question 6

Name the 5 types of sampling

Answer 6

• Random
• Volunteer
• Opportunity
• Systematic
• Stratified

Question 7

Explain random sampling

Answer 7

All members of the target population are put into a list and given a number – participants are selected “lottery style”, using a computer-based randomiser or picking numbers from a hat. All members of the target population have an equal chance of being selected.

Question 8

Evaluate random sampling

Answer 8

Pros:
- Representative of the target population
- Everyone has an equal chance of being chosen

Cons:
- Difficult to have access to
every member of the target
population
- Time consuming
- If anyone rejects or withdraws
their participation, the sample
becomes less random

Question 9

Explain volunteer sampling

Answer 9

Participants put themselves forward to be part of the research, usually in response to an advertisement
produced by the researcher.

Question 10

Evaluate volunteer sampling

Answer 10

Pros:
- Very little effort needed from
the researcher
- Makes finding participants for
more specific research easier

Cons:
- Less representative of the
target population - usually a specific type of
person volunteers (extroverts)

Question 11

Explain opportunity sampling

Answer 11

Made up of people who are easily obtained by the researcher, and who
are willing to take part in the research.

Question 12

Evaluate opportunity sampling

Answer 12

Pros:
- Quickest ways to
gather a sample
- Convenient for the
researcher
- Less time consuming

Cons:
- Not as representative of the
target population
- People may feel obligated to
participate depending on their
closeness to the researcher

Question 13

Explain systematic sampling

Answer 13

All members of the target population are put into a list and given a number – every nth person in this list is selected.

Question 14

Evaluate systematic sampling

Answer 14

Pros:
- Avoids researcher bias
(once the researcher has
established the system of
selection, they have no influence
over who is selected)
- More representative of the
target population

Cons:
- Takes a lot of effort to achieve
- Time consuming and
- Can be expensive

Question 15

Explain stratified sampling

Answer 15

The researcher identifies all the different subgroups within the target population and the sample is collected to specifically match the target population – a small number of participants are gathered from each
subgroup.

Question 16

Evaluate stratified sampling

Answer 16

Pros:
- Best method for getting a representative sample,
- Results and conclusions of the study are more generalisable

Cons:
- Time consuming, it can take a lot of effort and time to gather a
sample that is truly representative
- If any participants withdraw their consent, the sample becomes less representative