1.1 Paremeter

"A parameter is a value, usually unknown (and which therefore has to be estimated), used to represent a certain population characteristic. For example, the population mean is a parameter that is often used to indicate the average value of a quantity.
Within a population, a parameter is a fixed value which does not vary. Each sample drawn from the population has its own value of any statistic that is used to estimate this parameter. For example, the mean of the data in a sample is used to give information about the overall mean in the population from which that sample was drawn.
Parameters are often assigned Greek letters (e.g.
), whereas statistics are assigned Roman letters (e.g. s).

Valerie J. Easton & John H. McColl. Basic Definitions. Statistics Glossary V1.1, (2) . Retrieved from


A parameter is the value which addresses the feature or attribute of a population. When the parameter is calculated it is used to identify a quantitative characteristic based on the population mean. It always has a fixed value and does not fluctuate.



As we see the parameter underlies the entire population whereas a statistic underlies a sample population.