Research Methods - Sampling

What is Convenience sampling?

Opportunity sampling

What is Self-Selection sampling?

Volunteer sampling

Types of Porbability Sampling

Systematic sampling

• drawing numbers + recruiting every nth person

Cluster sampling

• randomly selecting groups within a population → prisoners

Multistage sampling

• randomly sampling specific people within the clusters

Stratified sampling

• different groups selected for representation (?) → recruiting based on ethnicity

Oversampling

• oversampling small groups to make up for small sample size

Random Sampling vs Random Assignment

Assignment assigns participants to groups at random to increase internal validity

What is Purposive sampling?

Certain groups that need to be studied are targeted

eg smokers

What are Nonprobability Samples?

Convenience

Purposive

Snowball

Quota

External validity is lower priority

• Is the biases within the sample relevant to what’s being studied