systematic sample

Placing the scientific instruments and doing the systematic sample collecting could come later.

It is however, much more efficient (if variance within systematic sample is more than variance of population).

The non-randomness of the quota sample (and, to some extent, the systematic sample) prevent computation of any measure of variability.

Systematic sampling is to be applied only if the given population is logically homogeneous, because systematic sample units are uniformly distributed over the population.

Several types of random samples are simple random samples, systematic samples, stratified random samples, and cluster random samples.

A recognized expert on the methods of qualitative research, Gerson relies primarily on original in-depth, life history interviews gathered from systematic samples to explain the links between processes of social and individual change.