3. Data Collection

Non-random sample types

Convenience, Purposive, Quota, Snowball

Random sampling types

Simple random, Stratified, Cluster (+multistage), Systematic

Convenience sampling

Participants are easy to reach

Purposive sampling

Specific individuals who can provide important info

Quota sampling

Requirement for number within the groups

Snowball sampling

Participants are asked to recommend others

Simple random sampling

Uses list of whole pop. and randomly select

Stratified sample

Combo of multiple random samples drawn from subgroups of pop.

Cluster sampling

Divide pop. Into cluster and randomly select some

Systematic sampling

Pop. is ordered and you pick every n-th individual