Statistical Sampling

Wikipedia says:

Sampling is that part of statistical practice concerned with the selection of individual observations intended to yield some knowledge about a population of concern, especially for the purposes of statistical inference. Each observation measures one or more properties (weight, location, etc.) of an observable entity enumerated to distinguish objects or individuals. Survey weights often need to be applied to the data to adjust for the sample design. Results from probability theory and statistical theory are employed to guide practice.

There's more to read in their entry.

I don't encourage entrepreneurs to go out and do surveys. They should, unless there's a compelling reason not to, rely on available research. Surveys, even if done yourself, cost money, resources better spent on other tasks. After all, what you want to do is create a baseline--what a market is like without you in it. That way you can measure your progress. That can best be done by extrapolation from existing literature. But if they do want to do some kind of survey, they should go to an expert rather than trying to figure it out on their own. They have plenty of other things to figure out on their own. Believe me, that used to be my business.

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