What is the best sample size for maximum variation sample?
For a single-stage sample, or at the grassroots level of sampling, it’s best to limit a maximum variation sample to no more than about 50 units. Above that number, interviewers get confused, and other methods, such as quota sampling and radial sampling, are simpler, and often more comprehensive. By combining those sub-samples of 50 or less in a multistage sample, the total sample can be thousands of people – but because of the additional effort involved, you wouldn’t do that unless there was no alternative. The largest I’ve tried was about 200, in clusters of 12 – but a quota sample (e.g. age group by sex by occupation type) might have been as representative, and would have needed a lot less supervision of interviewers.
