What is a Complex Sample Part 2: What is it and Why Would You Ever Want to Use One?

January 6th, 2014 by

In our last article, we talked about simple random samples.  Simple random samples are, well…simple, but they’re not always optimal or even possible.

Probability samples that don’t meet the assumptions of Simple Random Samples are called Complex Samples.

You’ll also hear the term Complex Survey, which is really just a survey that incorporates some sort of complex sampling design.  Because of their size and research goals, surveys are usually* the only type of research study that uses complex samples.

(*but not always.  I have seen intervention studies, for example, that used complex sampling).

What is a Complex Sample?

The most defining feature of a complex sample is that sample members do not have equal probability of being selected.

That sounds simple enough.  But… (more…)