Annotating cognates in phylogenetic studies of Southeast Asian languages

Compounding and derivation are frequent in many language families. As a consequence, words in different languages are often only partially cognate, sharing some but not all morphemes. While partial cognates do not constitute a problem for the phonological reconstruction of individual morphemes, they are problematic for phylogenetic reconstruction based on comparative word lists. We review current practices of preparing cognate-coded word lists and develop new approaches that make the process of cognate annotation more transparent. Comparing four methods by which partial cognate judgments can be converted to cognate judgments for whole words on a newly annotated data set of 19 Chinese dialect varieties, we find that the choice of conversion method has an impact on the inferred tree topologies that cannot be ignored. We conclude that scholars should take great care with cognate judgments in languages in which compounding and derivation are frequent and recommend always assigning cognates transparently.