There are 4 basic types of nonrandom samples:

1. Systematic: Listing all members of an accessible population and then selecting every 5th person in the list.

2. Quota: Nonrandom form of stratified random sampling.

3. Purposeful(Purposive): Selection of members which proved to provide relevant answers to research questions. There are several ways to do this:

a.)Typical case sampling: Selecting samples which the researcher believe to represent the norm.

b.)Extreme or deviant case: Focuses on cases which are unusual or special.

c.)Intensity sampling: Selecting the information-rich cases that show the phenomenon of interest intensely.

d.)Maximum variation: Encompassing the most amount of variation in the selection of participants. A key goal is ensuring heterogeneity.

f.)Homogeneous sampling:The opposite of maximum variation. Chief goal is to describe one subgroup of participant who have similar backgrounds and experiences, in depth.

4.Convenience: Most common least reliable strategy. Using samples which are at hand as in action researchs.

Sowell, Evelyn J.(2000). Educational Research: An Integrative Introduction. United States: McGraw-Hill.