diachronic study


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lon·gi·tu·di·nal stud·y

a study of the natural course of life or disorder in which a cohort of subjects is serially observed over a period of time and no assumptions need be made about the stability of the system.
Synonym(s): diachronic study

longitudinal study

An epidemiologic study that follows a population forward over time, evaluating the effects of one or more variables on a process. If individuals are followed, it is termed a longitudinal cohort study. If classes—e.g., age classes—are studied, it is a longitudinal cross-sectional study. Longitudinal studies are the converse of horizontal studies.
 
Examples
Cohort studies; case-control studies; Framingham Study in Massachusetts, US; Port Pirie study, an ongoing analysis of the long-term effects of blood lead levels on IQ.

di·a·chron·ic study

(dī-ă-kron'ik stŭd'ē)
A study of the natural course of a life or disorder in which a cohort of subjects is serially observed over a period of time and no assumptions need be made about the stability of the system.
References in periodicals archive ?
The section on "The Diachronic Study Mode" has two essays.
One era's nonsense, another's norm: diachronic study of Greek and the computer, Notis Toufexis.
Among the topics are a semantic map approach to a typology of impersonal constructions, impersonal constructs and accusative subjects in late Latin, the case of meteorological predication in Afroasiatic, a diachronic study of the impersonal passive in Ainu, and impersonal constructions in some Oceanic languages.
Although some general trends can be discerned, doing a diachronic study of tombs employing samples that are not firmly dated creates some methodological difficulties.
This awareness of and sensitivity to the effects of mediating texts is a particular strength in the essays of Fantasies of Troy, extending the volume's perspective and impact beyond the purview of early modern scholarship into a diachronic study of potential interest to scholars of the classical, medieval, and modern periods as well.
Past investigations in the area (Davies 1980; Flight 1976; Rahtz & Flight 1974; Stahl 1985) provided a resource that has been utilized as the foundation for an intensive diachronic study of the local archaeology.
Landoni's volume is divided into four long chapters that reflect the four principal avenues of investigation in her diachronic study.
The integration of MILLION into the English system of number words; a diachronic study.
Kaye, "Arabic/ziim/: A Synchronic and Diachronic Study," Linguistics 79 [1972]: 31-72).
Specific topics include: a diachronic study of the style of Longfellow, Menzerath's law for the smallest grammars, Romanian online dialect atlas, quantitative analysis of co-reference structures in texts, and the universality of Zipf's law for word frequencies.
The Particle u in the Rigveda: A Synchronic and Diachronic Study.