Models of lexical decay
David C. Kleinecke · 1965
Lexical decay is the phenomenon underlying the dating techniques known as "glottochronology" and "lexicostatistics." Much of the contraversial nature of work in this field is the result of extremely imprecise foundations and lack of attention to the underlying statistical and semantic models.A satisfactory semantic model can be found in the concept of semantic atom. Notwithstanding a number of philosophical objections, the semantic atom is an operationally feasible support for a lexicon which is a semantic subset of all possible meanings and at the same time, exhausts the vocabulary of a language. Lexical decay is the process by which the lexical item covering an atom is replaced by another lexical item.Exponential lexical preservation is, in this model, directly analogous to decay phenomena in nuclear physics. Consistency requires that the decay process involved in exponentially preserved vocabularies be a Poisson process. This shows how to form test vocabularies for dating and proves that presently used vocabularies are not correctly formed.Dialectation studies show that historically diverging populations must be modelled by correlated Poisson processes. Definitive statistical treatment of these questions is not possible at this time, but much desirable research can be indicated.