Sampling Flashcards
Define population
The target group of people being studied (based on age, gender, etc.)
Define participant
An individual who is recruited to take part in a psychological study
Define sample
The group of participants gathered to take part in the study, who represent the population.
Define representative
When the sample’s characteristics closely matches those of the target population.
Define generalisation
The extent to which the study’s conclusions can be applied to the broader population.
Define bias
When certain groups of the target population are over/under-represented within the sample (for various reasons)
Name the 5 types of sampling
- Random
- Volunteer
- Opportunity
- Systematic
- Stratified
Explain random sampling
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.
Evaluate random sampling
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
Explain volunteer sampling
Participants put themselves forward to be part of the research, usually in response to an advertisement
produced by the researcher.
Evaluate volunteer sampling
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)
Explain opportunity sampling
Made up of people who are easily obtained by the researcher, and who
are willing to take part in the research.
Evaluate opportunity sampling
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
Explain systematic sampling
All members of the target population are put into a list and given a number – every nth person in this list is selected.
Evaluate systematic sampling
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