Dan Wright Developing Algorithms for Computational Comparative Diachronic Historical Linguistics

Historical Linguistics ● Historical linguistics is the study of how language changes over time. ● Languages split into groups, forming a hierarchy or web of languages, each related to its ancestors ● All changes in language are completely regular, so they can be analyzed and to a degree discovered from the current state of the descendant languages.

Phonetics ● The fundamental unit of language is the phoneme. ● In order to analyze language, one must first devise a method to deal with phonemes. ● Phonemes can be classified on five axes, using the separations of the International Phonetic Alphabet.

Phoneme Categorization

Phoneme Storage Vowels Roundedness Openness Frontness Offset Consonants Voicedness Place of Articulation Method of Articulation Not used Vowel or Consonant

Correspondence ● My first attempts to analyze the web- structures of languages was by measuring correspondence between languages. ● I ran lists of words through algorithms which measured how much certain phonemes and axial structures matched up. ● I attempted to build a web of languages from the bottom up, connecting languages through correspondence.

● But there is a better way!

From the Top Down! ● My second approach to web formation was to start with all of the languages in one organization. ● I then separated them into languages which are more related to each other than a regressed hypothetical ancestor language. ● This was recursively applied to the new families.

Conclusion ● My top-down approach was able to somewhat reliably separate languages into their actual categories based on phonetics alone.