High Quality Content by WIKIPEDIA articles! Lexicostatistics is an approach to comparative linguistics that involves quantitative comparison of lexical cognates. 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.