Sampling techniques

Question 1

Explain random sampling and evaluate it

Answer 1

Random sampling - Every member of the population has an equal chance of being selected, it is achieved using a lottery method
AO3:
S - unbiased + representative if large enough
L - time consuming for the entire list

Question 2

Explain systematic sampling and evaluate it

Answer 2

Systematic sampling - Every nth person is selected from a list where the starting point is randomly
AO3:
S - no research bias + representative
L - if list has patterns it may not be representative

Question 3

Explain stratified sampling and evaluate it

Answer 3

Stratified sampling - People divided into subgroups based on characteristics e.g: gender, age. Participants are randomly selected from each subgroup proportionally
AO3:
S - more representative of population
L - time consuming and complex to organise

Question 4

Explain opportunity sampling and evaluate it

Answer 4

Opportunity sampling - Participants are selected based on who is available at the time
AO3:
S - quick, easy and cost-effective
L - highly biased + unrepresentative

Question 5

Explain volunteer sampling and evaluate it

Answer 5

Volunteer sampling - participants volunteer usually through adverts
AO3:
S - easy, participants are willing
L - volunteer bias (demand characteristics)