Viveka Velupillai

Explorations in automated language classification

An earlier paper, to which some authors of the present paper have contributed (Brown et al. 2008), describes a method for automating language classification based on the 100-item referent list of Swadesh (1955). Here we discuss a refinement of the method, involving calculation of relative stabilities of list items and reduction of the list to a shorter one by eliminating least stable items. The result is a 40-item referent list. The method for determining stabilities is explained, as well as a method for comparing the classificatory performance of different-sized reduced lists with that of the full 100-item list. A statistical investigation of the relationship of lexical similarity of languages to their geographical proximity is presented. Finally, we test the possibility that information involving typological features of languages can be combined with lexical data to enhance classificatory accuracy.

Automated dating of the world’s language families based on lexical similarity

This paper describes a computerized alternative to glottochronology for estimating elapsed time since parent languages diverged into daughter languages. The method, developed by the Automated Similarity Judgment Program (ASJP) consortium, is different from glottochronology in four major respects: (1) it is automated and thus is more objective, (2) it applies a uniform analytical approach to a single database of worldwide languages, (3) it is based on lexical similarity as determined from Levenshtein (edit) distances rather than on cognate percentages, and (4) it provides a formula for date calculation that mathematically recognizes the lexical heterogeneity of individual languages, including parent languages just before their breakup into daughter languages. Automated judgments of lexical similarity for groups of related languages are calibrated with historical, epigraphic, and archaeological divergence dates for 52 language groups. The discrepancies between estimated and calibration dates are found to be on average 29% as large as the estimated dates themselves, a figure that does not differ significantly among language families. As a resource for further research that may require dates of known level of accuracy, we offer a list of ASJP time depths for nearly all the world’s recognized language families and for many subfamilies.

Adding typology to lexicostatistics: a combined approach to language classification

Abstract The ASJP project aims at establishing relationships between languages on the basis of the Swadesh word list. For this purpose, lists have been collected and phonologically transcribed for almost 3,500 languages. Using a method based on the algorithm proposed by Levenshtein (Cybernetics and Control Theory 10: 707–710, 1966), a custom-made computer program calculates the distances between all pairs of languages in the database. Standard software is used to express the relationships between languages graphically. The current article compares the results of our lexicon-based approach with the results of a similar exercise that takes the typological variables contained in the WALS database as a point of departure. We establish that the latter approach leads to even better results than the lexicon-based one. The best result in terms of correspondence with some well-established genetic and areal classifications, however, is attained when the lexical and typological methods are combined, especially if we select both the most stable Swadesh items and the most stable WALS variables.

Pidgins, Creoles and mixed languages : an introduction

This lucid and theory-neutral introduction to the study of pidgins, creoles and mixed languages covers both theoretical and empirical issues pertinent to the field of contact linguistics. Part I presents the theoretical background, with chapters devoted to the definition of terms, the sociohistorical settings, theories on the genesis of pidgins and creoles, as well as discussions on language variation and the sociology of language. Part II empirically tests assumptions made about the linguistic characteristics of pidgins and creoles by systematically comparing them with other natural languages in all linguistic domains. This is the first introduction that consistently applies the findings of the Atlas of Pidgin and Creole Language Structures and systematically includes extended pidgins and mixed languages in the discussion of each linguistic feature. The book is designed for students of courses with a focus on pidgins, creoles and mixed languages, as well as typologically oriented courses on contact linguistics.

Glottochronology as a Heuristic for Genealogical Language Relationships

Abstract This paper applies a computerized method related to that of glottochronology and addresses the question whether such a method is useful as a heuristic for identifying deep genealogical relations among languages. We first measure lexical similarities for pairs of language families that are normally assumed to be unrelated, using a modification of the Levenshtein distance as our similarity measure. We then go on to study how the similarities are statistically distributed. The average similarity is slightly greater than zero, suggesting a small effect of sound symbolism. The upper tail of the distribution extends to similarities comparable to what is typically found for well-established families or highest-order subgroups of old families, but the pairs of unrelated families with the highest similarities contain only a few languages. We conclude that the method may work as a useful heuristic, provided that the number of languages compared is taken into account.