While the comparative method can imply relatedness, early comparative work was flawed by an emphasis of quantity of words that should be collected from each language. The demand for more words led to poor datasets, incorrect cognate pairings and due to cultural difference, sometimes a lack of appropriate cognates. This problem with linguistics was tackled in 1952 courtesy of Morris Swadesh, with his eponymous Swadesh list. The list comprised of 215 basic words that he believed would be common to every language, regardless of culture. Originally this was purely based on his own opinion \cite{Makihara_2006}, however later revisions would comprise of 4 main types of words: Basic nouns (including familial terms, objects found in nature and anatomical parts), basic verbs (including basic actions and reactions), basic adjectives (colours & relative temperatures) and pronouns (you, I, they, etc.) \cite{Heggarty_2012}. Swadesh's believe that these words were non-cultural led him to the idea that the words would evolve at the same rate regardless of language or population, due to their universal importance in communication. Over time Swadesh narrowed down the list to just 100 words, marked a change in linguistics emphasising the importance of a smaller selection of high quality data, more likely to be etymologically homologous. 
The Swadesh list has also not gone without criticism: The universality of the words was debated (which was one of the reasons Swadesh decreased the size of his list) and the lack of cultural influence on the basic vocabulary was questioned \cite{Sjoberg_1956}. Anthropologists and historical linguists at the time believed the applicability of glottochronology was overstated, and useful for only very rough time estimates. This removal of cultural consideration in language can to a certain extent be seen today in modern day biological approaches, where uncertainty is accounted for in Bayesian modelling.