Note to self about a possible project. This PLoS ONE paper: describes a method for inferring a hierarchy from a set of tags (and cites related work that is of interest). I've grabbed the code and data from http://hiertags-beta.elte.hu/home/ and put it on GitHub. Possible project Use Tibély et al. method (or others) on taxonomic names extracted from BHL text (or other) and see if we can reconstruct taxonomic classifications.