Estimand, estimator and estimation
- Estimand: Parameter in the population which is to be estimated in a statistical analysis
- e.g. mean age of the Swiss population
- Estimator: A rule for calculating an estimate of a given quantity based on observed data
- e.g. formula to calculate mean age in a (random) sample of the Swiss
- Estimate: e.g. actual mean age we calculated based on the sample
- The process of finding an estimate, or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable (value derived from the best information available)
- Rule (the estimator), the quantity of interest (the estimand) and its result (the estimate) are distinguished.