SSC Quickhelp

Prior to conducting research, the surveyor or researcher should determine reasonable sample sizes, based on mainly two considerations:

If your sample size is too big, the research cost may be too high for the value of the results one reaches.
If your sample size is too small, you won't even be able to reach valid conclusions.

Either way, you loose money and effort. Having a sensible sample size is of crucial importance in most research and surveys.

Until now, calculations of sample sizes were a matter of "sound sense", or dubious formulas not well understood by researchers. Though the literature is relatively old and specialised software packages allow to perform sample sizes calculations quite well, it appears that most researchers still don't use this material. Either because they are unaware of it, or because they don't understand it and don't want to invest a lot of time in this apparently simple subject.

Sample size calculator is meant to help:

It offers quick, but sound estimates for sample sizes in a variety of situations
It works like a wizard, offering the researcher only options he should care about.
It allows to choose corrections for different situations
It has an easy and flexible reporting functionality
It comes with an understandable content-rich help file (the text you are reading right now).

Please send your comments to Peter Doomen. This document was updated 21/12/2001.