Ceryle and "Grass Roots" Ontologies

FromSteal this bookmark!, Katharine Mieszkowski, Salon.com:
"But what‘s intriguing about43 Things isn‘t the voyeuristic itch it scratches, as we get to see so many people baring their heart‘s desire. What makes the site work is how it connects all these people to each other. By a simple software tweak known as tagging, this site and many others, like the photo siteFlickr and the bookmark-sharing systemdel.icio.us, have found a new way to organize information and connect people. The surprise is that the organizing itself is unorganized -- and yet it works.
On 43 Things you state a goal, such as "write a novel." That immediately links you to all the other people who have the exact same goal. But you also attach tags to your goal -- essentially key words that you choose -- such as "writing," "novel" and "fiction." Tags are not selected from any pre-codified hierarchy set by the site designers. They simply arise from the grass roots -- you and others like you. Now you‘re suddenly connected to everyone with similar goals, such as "write a good novel" and "write a book and have it published" and "finish my novel."
On reading this article, it strikes me that sites like 43 Things are based on some very similar assumptions to my own work. The Knowledge Representation field is full of researchers who talk about computer-based "ontologies," where the concepts and relationships between concepts are almost always very formally represented, where machine-based reasoning upon these structures is done in a very formal way, according to logical rules. This is anything but "grass roots," as one needs a level of expertise that only a handful of people in the world have. Furthermore, the big epistemological problem behind this entire approach is that people don‘t think or act in formal, logical ways, and I‘m yet to be convinced that the world itself operates according to those rules either. Why would one believe something so complex as the human mind operates on logic when even at the most base level of physics we‘re dealing with quantum mechanics? John Sowa talks about this issue in a tract calledKnowledge Soup (404K PDF).
It‘s been the crux of my own work to develop something that the Rest of Us can use. It unfortunately was the cause of a fair amount of friction between myself and one of my advisors in the KR field, such that he‘s no longer my advisor. He felt that my work "didn‘t provide any contribution" to the field, which is nonsense, it‘s that his approach to the field doesn‘t provide any contribution to the real world we live in, unless one actually believes the hoo-hah that words carry intrinsic meaning, absent any context or human interpreter. Much of the KR work I‘ve seen relies on this nonsensical presupposition. Even a dictionary tells otherwise. Of course, none of this has ever stopped a funded project from "success." The fundamental epistemological issues are all conveniently just swept under a rug.
Now, the limitations here are language. When someone makes a specific statement, we have to take it on faith that the words used by one person mean the same thing to others. This is obviously not true at all, but apparently works well enough that people can actually communicate with each other. There are errors, but life is iterative. The big deal is context, but that‘s a subject that itself deserves a great deal of thought (more than one blog entry).
So when I see something like this article on 43 Things, where people are just using normal language to create concepts and relationships between them, I take some heart. One has to remember that the words chosen don‘t have some kind of formal behind-the-scenes, mathematical model, but that doesn‘t make them un-reasonable. In fact, there‘s some [minor but] functional reasoning going on by 43 Things when it connects people up by statements they make about their goals and aspirations. It is machine reasoning, just not so complicated. But useful. And not pretending any formality. And in that, it shares a similar approach to Ceryle. Ceryle is about using a small set of existing relationship types (called Association Templates in Ceryle due to its Topic Map background), such that when someone uses one of those existing Associations they‘re tacitly agreeing to its definition. This is what would be called in more formal terms an "ontological commitment": i.e., by agreeing to use a term one is bound by its meaning, just like in real life.
So in Ceryle, there‘s three main ones (though once I have the Association Editor finished, you‘ll be able to make your own):
"is a" (class-instance) e.g., "John [instance] is_a human [class]."
"kind of" (superclass-subclass) e.g., "Human [subclass] kind_of Mammal [superclass]"
"has" (has facet or property) e.g., "John [faceted] has brown eyes [facet]."
The latter terminology is derived from Faceted Classification (FC, akaFaceted Analytical Theory), an organizational schema coming from library science. The words "property", "attribute", "characteristic", etc. might be considered synonyms, but "facet" is important because by bringing in the FC schema it implies that the specific facet itself fits into a hierarchy, and this hierarchy comes from the superclass-subclass Associations it has within the current ontology. In this way we can understand that brown eyes are a particular kind of characteristic, and in fact the whole structure of facets and facet relationships includes cardinality (how many), data typing, and measurement (such as what units a facet might be measured in). Not to make this discussion any more complicated, but in FC each facet fits into a tree structure, whereas in Ceryle it fits into a graph. In fact, the Topics acting as facets aren‘t considered special in the ontology — they‘re just Topics playing the role of facet in a facet Association. More on that later...
There are plans and partial implementations of all of this latter stuff in Ceryle, as well as modules for mereology, topology, and other important domains, and I hope to flesh this kind of thing out more in the future. It‘ll be how you add a birthdate and deathdate to a person, with Ceryle knowing that they‘re a particular kind of date and being able to do certain kinds of reasoning based on them, such as being able to set all events within a graph into a timeline.
There‘s a lot of different ontological and epistemological issues that need to be addressed, another being subject identity: how does one ascertain when two subjects are actually identical. Identity is a slippery and tricky concept. By "identical" I don‘t mean equal but equivalent, and additionally, equivalent within a context. Even subject identity is contextual.
This whole "grass roots" approach to computer-based ontologies is what about 95% of my entire research has been about. If that isn‘t a contribution to the Knowledge Representation field, I guess the field isn‘t much of a contribution to the grass roots either.
I don‘t believe it.