StatisticalPopulation
A StatisticalPopulation is a set of instances of a certain given type that satisfy some set of constraints. The property populationType is used to specify the type. Any property that can be used on instances of that type can appear on the statistical population. For example, a StatisticalPopulation representing all Persons with a homeLocation of East Podunk California would be described by applying the appropriate homeLocation and populationType properties to a StatisticalPopulation item that stands for that set of people. The properties numConstraints and constraintProperty are used to specify which of the populations properties are used to specify the population. Note that the sense of "population" used here is the general sense of a statistical population, and does not imply that the population consists of people. For example, a populationType of Event or NewsArticle could be used. See also Observation, where a populationType such as Person or Event can be indicated directly. In most cases it may be better to use StatisticalVariable instead of StatisticalPopulation.