Steve Pepper begins by talking about Vannevar Bush, whose influence on the Web has been profound. Bush was concerned with finding info, says Steve. His aim was to model how we find info on how the human mind works, i.e., by association. But, says Steve, Bush’s memex revolved entirely around documents, which is not how we think. [Caution: Live-blogging!]

Documents are about subjects. Subjects exist as concepts in our brains. They’re connected by a network of associations. Docs are how we happen to capture and communicate ideas. “Hypertext has been barking up the wrong tree” ever since the memex. (Steve then couches this more softly, acknowledging how much he loves the Web, etc.) We should be organizing information around topics/subjects, not around documents.

Why? Because topic maps reflect how we think. That’s why topic maps are ideal fo web sites. They’re subject-based associative. See topicmaps.com.

Steve counters the impression that topic maps are a portal technology. They were invented in 1991, before the Web. They “just turned out to be ideal for the purpose.” Until recently, they were mainly used for portals, but now they’re used increasingly to represent domains of knowledge. TMs are bigger than Topics, Associations, and Occurrences (TAO), for knowledge has a context. The concept of scope enables the rexpression of contextual validity, enabling multiple viewpoints. This makes topic maps more than a simple semantic tech. Semantics are decontextualized meaning, whereas pragmatics is contextuaiized meaning. See www.hoyre.no

Merging “is the single most powerful feature of topic maps.” Merging was the original motivation for topic maps, merging multiple indexes. It enables a “global knowledge federation.” You can arbitrarily merge any two topic maps. That can’t be done with relational databases or XML documents. But how to make it useful? It vcan’t be done by relying on names since every subject has multiple names, says Steve. The only solution for computers is identifiers. A topic in a topic map is a symbol that represents something in the real world, says Steve. He quotes the ISO definition: “A subject is any ‘thing’ whatsoever, whether or not it exists or has any other specific characteristics, about which anything whatsoever may be asserted by any means whatsoever.”

Meaning is expressed through the relationship between the representation and that to which it refers. Subject identifiers are central to topic maps. For example, which Steve Pepper wrote the letter of protest to the ISO committee? There’s a Steve Pepper in NJ who has a CD called “The Information Age.” But if you look at the metadata on the PDF of Steve’s letter, there’s a URI that describes Steve. This allows humans to disambiguate. At the moment there’s no good way to register such identities. “PSIs [Published Subject Identifiers] are perhaps not the final answer, but they’re a pretty good stopgap” and can easily be remapped if something else turns out to be the answer.

Steve ends by asking Microsoft to become more subject-centric. Windows is highly document-centric he says. He wants a desktop that shows him the subjects and topics he cares about, rather than folders and apps. Although there are some Semantic Web people working on a semantic desktop, Steve thinks Topic Maps is better for human-facing representations of knowledge. Why not have an entire subject-centric operating system, he asks: NLP for categorizing docukents, p2p, facilities for merges, etc.

Topic maps started out as a way to merge indexes, Steve says. It turned into a knowledge representation formalism. Now it’s the flag-bearer for subject-centric computing. Subject-centric computing is a paradigm shift, Steve says, comparing it to object-oriented programming, and then to the Copernican revolution. [Tags: topic_maps steve_pepper ]

Categories: conference coverage, everythingIsMiscellaneous, knowledge, metadata