Population (epidemiology)

Population is defined by exact definitions of its objects. Objects of a population are given by enumeration or by explicit rule (for example given common property) that enables us to decide for any object whether belongs to given population or not (e.g.: everybody in a town, all male workers in a factory, everybody with hypertension).

A population can be finite or infinite. Finite populations are, for example, demographic populations. Population can also be considered as an abstract idea of a collection of objects. These objects are described by variables:
 * Qualitative variables: Properties that cannot be measured but only described in words (family status, level of pain).
 * Quantitative variables: Can be measured and expressed as a number (weight, BP, BMI).

Related articles

 * Population
 * Descriptive Studies
 * Analytical Studies