ABSTRACT
Before the unbiased estimator, we need to explain a couple of other terms in biostatistics that would make it easy to understand this term. First, technically, a statistic is something we calculate on the basis of sample values. Note that this is singular, the plural of which is statistics. Sample mean, sample median, sample standard deviation (SD), etc. are all statistics in this sense. The values of the sample statistics vary from sample to sample, i.e., they are also variables. Second, the sample statistic formula used to estimate the value of the population parameter is called its estimator. For example, population mean μ is estimated by sample mean x —thus, x is the estimator of μ. Generally, the corresponding sample analogue is the estimator of any population parameter. Sample SD is the estimator of the population SD, and sample median is the estimator of the population median. Whether or not they are good at providing an adequate estimate is another question.
