Taxonomy

At their core, taxonomies and other classification systems are ways of organizing and managing knowledge. To understand the history of classification systems, it behooves us to explore the history of thinking about knowledge. So what is knowledge? The Greek philosopher Plato defined it as “justified true belief”. However, the twentieth-century writer Bertrand Russell commented that “at first sight it might be thought that knowledge might be defined as belief which is in agreement with the facts. The trouble is that no one knows what a belief is, no one knows what a fact is, and no one knows what sort of agreement between them would make a belief true.”

The workings of a taxonomy or thesaurus in a database or website can seem mysterious. Let’s take a look behind the scenes. irst of all, we need the taxonomy or thesaurus in digital form, either as a separate file or as it exists in a specialized software application. The screenshot below is from the editorial user interface of a thesaurus software application.

Over the past several weeks, we have looked at various topics involving taxonomies and thesauri. And we have seen that controlled vocabularies are an important part of search and browsing. But how are taxonomies put to use? What about the terms? Where do they go? Exactly how are they put to use in search? What are the different ways that a taxonomy can be used in search?