Compare methods

	Direct Standardization	Kitagawa Decomposition
Field	Demography	Demography
Family	Process / pipeline	Process / pipeline
Year of origin	2001	1955
Originator	Classical demographic method (formalized by Preston, Heuveline & Guillot)	Evelyn M. Kitagawa
Type	Rate adjustment by reweighting to a standard population	Arithmetic decomposition of a difference between two summary rates
Seminal source	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512	Kitagawa, E. M. (1955). Components of a difference between two rates. Journal of the American Statistical Association, 50(272), 1168–1194.
Aliases	Directly standardized rate, Age-standardized rate, Direct method of standardization, Doğrudan Standardizasyon	Components-of-difference method, Rate decomposition, Standardization decomposition, Kitagawa Ayrıştırması
Related	4	4
Summary	Direct standardization is a demographic technique that makes summary rates comparable across populations by applying each population's group-specific rates — most often age-specific death or disease rates — to a single, common standard population structure. The resulting directly standardized rate answers a counterfactual question: what would the crude rate be if every population had the same age (or other) composition? It removes the confounding effect of differing population structure so that genuine differences in underlying risk can be compared on a level footing.	Kitagawa decomposition is a demographic technique that splits the difference between two summary rates — such as two crude death rates, birth rates, or prevalence figures — into the part attributable to differences in the underlying group-specific rates and the part attributable to differences in population composition. Introduced by Evelyn Kitagawa in 1955, it answers whether a gap between two populations reflects genuinely different risks or merely a different age (or other) structure.