Point Estimaton

Point estimation refers to the use of a single statistic (number calculated from the data in a sample) as an estimate of a parameter (a number calculated from all of the measurements in a population).

At the very simplest level you can use the sample version of the parameter of interest as a point estimate. Examples

• A point estimate of the population mean is the sample mean
• A point estimate of the population variance is the sample variance
• A point estimate of the population proportion is a sample proportion

Why say "a point estimate" instead of "the point estimate"? Because we often have choices for the point estimate: I could use a trimmed mean as a point estimate of a mean, for example.

There are drawbacks in using point estimates rather than some type of interval estimate, but coverage of those is fodder for another question (or another responder to this post)