Lexicostatistics

Lexicostatistics is a method of comparative linguistics that involves comparing the percentage of lexical cognates between languages to determine their relationship. Lexicostatistics is related to the comparative method but does not reconstruct a proto-language. It is to be distinguished from glottochronology, which attempts to use lexicostatistical methods to estimate the length of time since two or more languages diverged from a common earlier proto-language. This is merely one application of lexicostatistics, however; other applications of it may not share the assumption of a constant rate of change for basic lexical items. The term "lexicostatistics" is misleading in that mathematical equations are used but not statistics. Other features of a language may be used other than the lexicon, though this is unusual. Whereas the comparative method used shared identified innovations to determine sub-groups, lexicostatistics does not identify these. Lexicostatistics is a distance-based method, whereas the comparative method considers language characters directly. The lexicostatistics method is a simple and fast technique relative to the comparative method but has limitations (discussed below). It can be validated by cross-checking the trees produced by both methods. Lexicostatistics was developed by Morris Swadesh in a series of articles in the 1950s, based on earlier ideas. The concept's first known use was by Dumont d'Urville in 1834 who compared various "Oceanic" languages and proposed a method for calculating a coefficient of relationship. Hymes (1960) and Embleton (1986) both review the history of lexicostatistics. The aim is to generate a list of universally used meanings (hand, mouth, sky, I). Words are then collected for these meaning slots for each language being considered. Swadesh reduced a larger set of meanings down to 200 originally. He later found that it was necessary to reduce it further but that he could include some meanings that were not in his original list, giving his later 100-item list.