I noticed the followingRDF Interest Group IRC chat log discussing my recent post More on RDF, The Semantic Web and Perpetual Motion Machines in my referrer logs. I found the following excerpts quite illuminating
15:43:42 <f8dy> is owl rich enough to be able to say that my <pubDate>Tue, Nov 11, 2003</pubDate> is the same as your <dc:date>2003-11-11</dc:date> 15:44:35 <swh> shellac: I believe that XML datatypes are... ... 16:08:15 <f8dy> that vocabulary also uses dates, but it stores them in rfc822 format 16:08:51 <f8dy> 1. how do i programmatically determine this? 16:08:58 <JHendler> ah, but you cannot merge graphs on things without the same URI, unless you have some other way to do it 16:09:02 <f8dy> 2. how do i programmatically convert them to a format i understand? ... 16:09:40 <shellac> 1. use ... 16:10:13 <shellac> 1. use a xsd library 16:10:32 <shellac> 2. use an xsd library ... 16:11:08 <JHendler> n. use an xsd library :-> 16:11:30 <shellac> the graph merge won't magically merge that information, true 16:11:34 <JHendler> F: one of my old advisors used to say the only thing better than a strong advocate is a weak critic
15:43:42 <f8dy> is owl rich enough to be able to say that my <pubDate>Tue, Nov 11, 2003</pubDate> is the same as your <dc:date>2003-11-11</dc:date>
15:44:35 <swh> shellac: I believe that XML datatypes are...
...
16:08:15 <f8dy> that vocabulary also uses dates, but it stores them in rfc822 format
16:08:51 <f8dy> 1. how do i programmatically determine this?
16:08:58 <JHendler> ah, but you cannot merge graphs on things without the same URI, unless you have some other way to do it
16:09:02 <f8dy> 2. how do i programmatically convert them to a format i understand?
16:09:40 <shellac> 1. use
16:10:13 <shellac> 1. use a xsd library
16:10:32 <shellac> 2. use an xsd library
16:11:30 <shellac> the graph merge won't magically merge that information, true
16:11:34 <JHendler> F: one of my old advisors used to say the only thing better than a strong advocate is a weak critic
This argument cements my suspicions that the using RDF and Semantic Web technologies are a losing proposition when compared to using XML-centric technologies for information interchange on the World Wide Web. It is quite telling that none of the participants who tried to counter my arguments gave a cogent response besides "use an xsd library" when in fact anyone with a passing knowledge of XSD would inform them that XSD only supports ISO 8601 dates and would barf on RFC 822 if asked to treat them as dates. In fact, this is a common complaint about them from our customers w.r.t internationalization [that and the fact decimals use a period as a delimiter instead of a comma for fractional digits].
Even in this simple case of mapping equivalent elements (dc:date and pubDate) the Semantic Web advocates cannot provide a solution to how their vaunted ontolgies can provide a solution to a problem the average RSS aggregator author solves in about 5 minutes of coding using off-the-shelf XML tools. It is easy to say philosphically that dc:date and pubDate after all, they are both dates, but another thing to write code that knows how to treat them uniformly. I am quite surprised that such a straightforward real-world example cannot be handled by Semantic Web technologies. Clay Shirky's The Semantic Web, Syllogism, and Worldview makes even more sense now.
One of my co-workers recently called RDF an academic plaything, after seeing how many of its advocates ignore the difficult real world problems faced by software developers and computer users today while pretending that obtuse solution to trivial problems are important, I've definitely lost any interest I had left in investigating any further about the Semantic Web.