The group of persons or other elements that are the object of research and
to which any analytic results refer. Age, nationality, and residence
commonly help to delineate a given universe, but any of a number of factors
may be involved, such as sex, race, income, veteran status, criminal
convictions, etc. The universe may consist of elements other than persons,
such as housing units, court cases, deaths, countries, etc. In general, it
should be possible to tell from the description of the universe whether a
given individual or element (hypothetical or real) is a member of the
population under study. More information on this element, especially its
allowed attributes, can be found
in the references.