When you look at the Library of Congress Subject headings as individual entries it’s almost impossible to understand just how confused much of the hierarchical reference structure has become.
I’ve written some code to generate graphical representations for the Broader Terms of entries in the LCSH. The starting term appears at the bottom of the graph; according to the rules, this term is a specialization of every other term on the graph. Top level terms are highlighted using double circles.
Layout and rendering is courtesy of the wonderful graphviz (AT&T Research). I have generated dot files for all entries in the LCSH; I need to set up an dynamic renderer so they can be viewed online, but a p7zip archive raw dot is available here. (5M compressed, 672M uncompressed)
Lets see what the LCSH has to tell us about Doorbells.
Doorbells are a Social science. Doorbells are Souls. Doorbells are even Ontologies – which would explain why Protege keeps beeping at me. But most of all, Doorbells are mammals.
Obviously this conclusion is absurd. Everyone knows that doorbells aren’t hairy. But where are the errors that lead us to this mistaken conclusion, and how can we start to correct them? That’s the subject of tomorrow’s post.