Re: Was RDF started in 1989? Then why was it lost?

> Take a look at the graphic [1] at the top of Tim Berners-Lee's original
> proposal for the WWW [2].  The similarities between that image and a RDF
> graph are remarkable!  Is RDF a direct descendent of that work?

They have a common ancestor in Semantic Networks.  According to one
source [1]: "A semantic network ... is a directed graph consisting of
vertices which represent concepts and edges which represent semantic
relations between the concepts....  It is possible to represent
logical descriptions using semantic networks such as the Existential
Graphs of Charles S. Peirce [1839-1914] or the related Conceptual
Graphs of John F. Sowa....  Semantic Nets were first invented for
computers by Richard H. Richens of the Cambridge Language Research
Unit in 1956 as an "interlingua" for machine translation of natural
languages. They were developed as "semantic networks" for knowledge
representation and reasoning by M. Ross Quillian in 1966."

> Why did
> the linking mechanism for HTML drift from "semantically useful" arcs to
> generic anchors?
>                     Why was the originally intended linking concept
> lost and supplanted with the less-effective system predominately used
> now?

It's not clear to me that hypertext links and have all that much in
common with arbitrary 2-place relations.  HTML has ample features for
specifying types of hypertext links, and they have not caught on as
far as I can tell.  (I finally have a browser (Opera 7) which actually
uses <link rel=...> data, in 2003.)  But what does that kind of link
have in common with an RDF predicate?   

I guess you can view clicking on a link as performing a query on the
triple
    <from> ht:link <to>
where "from" and "to" identify ranges of document content.   And one
might reason about those links (as eg Google does), but what does that
really have in common with general reasoning about 2-place predicates?

    -- sandro

[1] http://www.wikipedia.org/wiki/Semantic_network

Received on Tuesday, 22 April 2003 23:12:21 UTC