Mapping the dimensions of linguistic distance: A study on South Ethiosemitic languages

We measured the distance among selected South Ethiosemitic languages from three dimensions: structural, functional and perceptual. The main objectives of our study was to determine the relationship among these three dimensions of linguistic distances, to re-examine previous classifications of the languages, and to measure the degree of mutual intelligibility among the language varieties. We determined the structural distance by computing the lexical and phonetic differences. The phonetic distance was computed using the Levenshtein algorithm. A Word Categorization test was adopted from Tang and van Heuven (2009) to measure the functional distance or the degree of intelligibility. A self-rating test, based on the recordings of 'The North Wind and the Sun' was administered to measure the perceptual distance among the languages. Then we performed a cluster analysis using Gabmap. Multidimensional scaling was employed for the cluster validation. The results of our study show that the selected South Ethiosemitic languages can be classified into five groups: {Chaha, Ezha, Gura, Gumer}, {Endegagn, Inor}, {Muher, Mesqan}, {Kistane} and {Silt'e}. Moreover, the language taxonomies obtained from the measures of the three dimensions of distance are very similar, and they are generally comparable to the classifications previously proposed by historical linguists. There is also a very strong correlation among the three dimensions of distance. Furthermore, the Word Categorization test results show that the majority of these languages are mutually intelligible with the exception of Silt'e.