Sampling techniques

Question 1

What are the 5 sampling techniques?

Answer 1

• Random sampling
• Opportunity sampling.
• Volunteer sampling.
• Systemic sampling.
• Stratified sampling.

Question 2

Random sampling

Answer 2

All ppts from the target pop have an equal chance of being selected (without bias/ ‘out of a hat’).
+= unbiased.
-= Time consuming.
-= May still not be representative.

Question 3

Opportunity sampling

Answer 3

• Select people who are available and willing to take part.
  += quick, easy and convenient.
  -= researcher bias.
  -= unrepresentative (cannot be generalised).

Question 4

Volunteer sampling

Answer 4

• ppts put themselves forwards for the research, usually through responding to an advert.
  += convenient.
  -= volunteering bias.
  -= unrepresentative (cannot be generalised).

Question 5

Systematic sampling

Answer 5

• The target population is arranged in some sort of order, then every ‘nth’ person is selected.
  += avoids researcher bias.
  -= Time consuming.
  -= still may not be representative.

Question 6

Stratified sampling

Answer 6

• The researcher identifies the different types of people that make up the target population + works out the proportion of the population each sub-group represents. Each sub group then needs to be proportionally represented in a sample.
  += avoids researcher bias.
  += designed to be representative.
  -= Very time consuming.