RDF and Semantic Web: can we reach escape velocity?
Jenni Tennison’s slides from TPAC 2010 are an interesting insight into how an “insider” views the current state of RDF and the Semantic Web.
I disagree with her on a couple of crucial points:
RDF’s only revolution, but the key one, is using URIs to name things, including properties and classes
identifying things with URIs does two really useful things
- disambiguates, enabling joins with other data using same URI
- mash-ups beyond mapping things on a Google Map
- provides something at the end of the URI
- extra information, explanation, context
- in a basic entity-attribute-value model that enables combination without either up-front agreement or end-user jiggerypokery
First, the “identifying things with URIs” is re-use of a very old idea, the perfect language, which has a universal and unbroken record of failure. (see my Blast from the Past and citations therein.)
Second, how is combination possible without either up-front agreement or end-user jiggerypokery?
Combining information without either up-front agreement or end-user jiggerypokery is why we get such odd search results now.
Let’s take a simple example. Search for “democracy” and see what results you get.
Now, do you really think that “democracy” (limiting my remarks to the US at the moment) from documents in the 18th and 19th centuries means the same thing as “democracy” after the fall of slavery but prior to women getting the right to vote? Or does it means the same thing as it does today? Or does it mean the same thing as its use in Egypt, where classes other than the moneyed ones may be favored?
No doubt you will say that someone could create URIs for all those senses of democracy, which is true, but the question is will we use them consistently? The answer to that has been no up to this point.
People are inconsistent, semantically speaking and there is no showing that is going to change.
Which brings me to the second major area of my disagreement.
RDF and the Semantic Web are failing (present tense) because they are the answer to a problem RDF and Semantic Web followers are interested in solving.
But not the answer to problems that interests anyone else.
At least not enough to pay the price of RDF and the Semantic Web.
To be fair, topic maps faces the same issue.
But at least topic maps started off with a particular problem (combining indexes) and then expanded to be a general solution.
The Semantic Web started off as a general solution in search of problems that would justify the cost of adoption. Not the best strategy.
I do like Jenni’s emphasis on assisting governments to make their data usefully available. That is a good thing and one that we agree on.
Both topic maps and RDF/SW need to analyze the problems of governments (and others) in making such data available.
Then, understanding the issues they face, derive as low cost a solution as possible within their paradigms to solve that problem.
That could involve URIs, for example, assuming there was a URI + N properties serve to identify a subject protocol.
Not that such a protocol makes us any more semantically consistent, but having more than one property to be inconsistent about, may (emphasis on may) reduce the range of semantic inconsistency.
Take my democracy example. If I had http://NotRealURI/democracy and a property of range, 1800-1850 and to match my sense of democracy required matching both the URI and the date range, that would be a step towards reducing semantic inconsistency.
It is the lack of a requirement that more than one property be matched for identity that underlies the technical failure of RDF/Semantic Web.
Its social failure is in not answering questions that are of interest to developers and ultimately users.
Providing useful answers to problems, seen by users as problems, is the way forward for both topic maps and RDF/Semantic Web.