This article by Clay Shirky is a good encapsulation of the computer/GIScientist understanding of ontology that is rapidly entering geography and especially mapping and GIS:
It is a rich irony that the word “ontology”, which has to do with making clear and explicit statements about entities in a particular domain, has so many conflicting definitions. I’ll offer two general ones.
The main thread of ontology in the philosophical sense is the study of entities and their relations. The question ontology asks is: What kinds of things exist or can exist in the world, and what manner of relations can those things have to each other? Ontology is less concerned with what is than with what is possible.
Shirky is right that ontology has many definitions, though he then confuses this statement by offering only one as the definition: in his words ontology is “essence, “Is-ness.”” Of course, philosophers will recognise this definition, and a classic one at that: objects with properties ie., Arisotelian substance or predicate ontology. This tradition had already been challenged in the 1920s by Martin Heidegger who replaced ontology as “is” with “being” and essence with existence. Today we would see Shirky’s definition of ontology as rather covering the “ontic” rather than the ontological.
Nevertheless, it’s important to get to grips with this kind of ontology-speak, because as the rest of Shirky’s article discusses it is being applied to some really interesting problems, namely how we sort information, and by extension how we access and use information.
One fascinating aspect of this problem has emerged over the course of the development of the more interactive web, or web 2.0, that changes the game from just downloading information (web 1.0) to contributing to it. In geography this is playing out as various forms of participatory geography: volunteered geographic information (VGI), geolocated pictures, tracks and locations, geotagging, and what is sometimes called the semantic web.
The journal I edit, Cartographica, has a special section in its latest issue of how ontologists are approaching the problem of redoing the US National Atlas (or any other large scale mapping project), many of whom draw on this tradition of ontology for their schemas. To me, the most interesting aspect of this are bottom-up categories, which need not be commensurable or static, are deeply meaningful to individuals and yet sharable.
As this fascinating article points out though, the problem of the “universal book” and data organization, access, retrieval and interrelationships long predates the internet. There was for example Paul Otlet:
In 1934, years before Vannevar Bush dreamed of the memex, decades before Ted Nelson coined the term “hypertext,” Paul Otlet envisioned a new kind of scholar’s workstation: a moving desk shaped like a wheel, powered by a network of hinged spokes beneath a series of moving surfaces. The machine would let users search, read and write their way through a vast mechanical database stored on millions of 3×5 index cards.
Having just come back from the National Archives, where information discovery and retrieval are often dodgy at best (print-only finding aids, stapled “cheatsheets” for use by the archivists with different but similar dates lying around on battered ring binders, frank admissions by the staff that the online catalog covers only as small fraction of even the top-level categories–and this for a reasonably popular “record group” the OSS), well, I can certainly relate.
The quote in the post title comes from Shirky’s description of Yahoo’s attempt at classifying the web back in the “earlies.” He goes on to pull this system, which the “professional ontologist” had devised, apart. With a powerful search engine like Google, you don’t need categories just good tagging (metadata).
“Ontology” may (or may not) be good for small technical domains (and even then bottom-up looks more useful) but for getting at lived human existence, it seems hopeless. Here in contrast is Jeremy Wood’s lived map of Warwick campus, which he made by walking it with a GPS and then making a map form the traces:
The Warwick campus, produced through GPS traces by Jeremy Wood. A map traversed at 1:1 scale, the scale of lived human experience.
Philosophers have a lot to contribute to these issues, not just formal philosophers such as Heidegger but (obFoucault) people who talk about archives, genealogy and epistemology, and the production of knowledge.
(Thanks to John Krygier for the Paul Otlet link.)