Latest revision as of 07:13, 11 February 2010

Data are called provisional¹ if they are based on incomplete or insufficiently controlled observations. They are replaced by final² data when the observations are complete. Rates based on such data are called provisional rates³ and final rates⁴ respectively. Where unexpected information becomes available after figures have already been published, revised rates⁵ may be issued. The expression corrected rate⁶ usually implies that defective data or inappropriate methods have yielded results which are either misleading or of limited value for the purpose in hand and that an effort has been made to correct this, e. g. correction for under-enumeration, correction for migration, correction for seasonal movement. Standardized rates⁷ or adjusted rates⁷ are designed to make it possible to compare different populations with respect to a variable, e. g. fertility or mortality, where the influence of another variable e. g. age, is held constant. The term corrected rate⁷ has been used by some demographers as a synonym for standardized rate. Unstandardized rates are called crude rates⁸. Although they may be used to measure actual trends, false inferences may result from their uncritical use when populations with different structures (144-4) are compared.
(It should be emphasized that there is no uniformly accepted terminology for the subjects mentioned in this paragraph and that the terms are often used rather loosely.)
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