"The term 'hunk' is not only an English word, but also a cell type (human natural killer) and a gene (hormonally upregulated Neu-associated kinase). A search for the term 'hunk' in PubMed gives references to all three contexts. These semantic variables make information retrieval and analysis very inefficient and ineffective. Searching outside one's area of expertise, where one is unlikely to be familiar with the nomenclature, can be extremely challenging. Moreover, what we also need is a way to control the context of computational searches, so that concepts that have different meanings, in different contexts, can be retrieved appropriately. While human beings are able to decipher the context of different articles containing for example the term 'hunk', computers are much less able to do so.
The use of ontologies is a key step...It is a very effective way to structure biology or chemistry in a way that helps scientists to understand the context and relationships that exist between terms in a specialised area of interest."
BioWisdom on The use of ontologies in drug discovery.