Presentation

Last Tuesday, TimBL started to gripe that the WWW2007 program had lots of stuff that he wanted to see all at the same time; we both realized pretty soon: that's a sign of a great conference.

That afternoon, Harry Halpin and I gave a GRDDL tutorial. Deploying Web-scale Mash-ups by Linking Microformats and the Semantic Web is the title Harry came up with... I was hesitant to be that sensationalist when we first started putting it together, but I think it actually lived up to the billing. It's too bad last-minute complications prevented Murray Maloney from being there to enjoy it with us.

For one thing, GRDDL implementations are springing up all over. I donated my list to the community as the GrddlImplementations wiki topic, and when I came back after the GRDDL spec went to Candidate Recommendation on May 2, several more had sprung up.

What's exciting about these new implementations is that they go beyond the basic "here's some RDF data from one web page" mechanism. They're integrated with RDF map/timeline browsers, and SPARQL engines, and so on.

The example from the GRDDL section of the semantic web client library docs (by Chris Bizer, Tobias Gauß, and Richard Cyganiak) is just "tell me about events on Dan's travel schedule" but that's just the tip of the iceberg: they have implemented the whole LinkedData algorithm (see the SWUI06 paper for details).

With all this great new stuff popping up all over, I felt I should include it in our tutorial materials. I'm not sure how long OpenLink Virtuoso has had GRDDL support (along with database integration, WEBDAV, RSS, Bugzilla support, and on and on), but it was news to me. But I also had to work through some bugs in the details of the GRDDL primer examples with Harry (not to mention dealing with some unexpected input on the HTML 5 decision). So the preparation involved some late nights...

I totally forgot to include the fact that Chime got the Semantic Technologies conference web site using microformats+GRDDL, and Edd did likewise with XTech.

But the questions from the audience showed they were really following along. I was a little worried when they didn't ask any questions about the recursive part of GRDDL; when I prompted them, they said they got it. I guess verbal explanations work; I'm still struggling to find an effective way to explain it in the spec. Harry followed up with some people in the halls about the spreadsheet example; as mnot said, Excel spreadsheets contain the bulk of the data in the enterprise.

One person was even followingn along closely enough to help me realize that the slide on monotonicity/partial understanding uses a really bad example.

The official LinkedData session was on Friday, but it spilled over to a few impromptu gatherings; on Wednesday evening, TimBL was browsing around with the tabulator, and he asked for some URIs from the audience, and in no time, we were browsing protiens and diseases, thanks to somebody who had re-packaged some LSID-based stuff as HTTP+RDF linked data.

Giovanni Tummarello showed a pretty cool back-link service for the Semantic Web. It included support for finding SPARQL endpoints relevant to various properties and classes, a contribution to the serviceDescription issue that the RDF Data Access Working Group postponed. I think I've seen a few other related ideas here and there; I'll try to put them in the ServiceDescription wiki topic when I remember the details...

Chris Bizer showed that dbpedia is the catalyst for an impressive federation of linked data. Back in March 2006, Toward Semantic Web data from Wikipedia was my wish into the web, and it's now granted. All those wikipedia infoboxes are now out there for SPARQLing. And other groups are hooking up musicbrainz and wordnet and so on. After such a long wait, it seems to be happening so fast! 

Speaking of fast, the Semantic MediaWiki project itself is starting to do performance testing with a full copy of wikipedia, Denny told us on Friday afternoon in the DevTrack.

Also speaking of fast, how did OpenLink go from not-on-my-radar to supporting every Semantic Web Technology I have ever heard of in about a year? I got part of the story in the halls... it started with ODBC drivers about a decade ago, which explains why their database integration is so good. Kingsley, here's hoping we get to play volleyball sometime. It's a shame we had just a few short moments together in the halls...

I went to the 1st International HASTAC Conference, April 19-21, 2007 at Duke University in Durham, NC, USA. My stated role was to tell the story of How the W3C Process Got Its Stripes to this humanities research community on a The World Wide Web Evolves panel that Harry Halpin arranged.

After a short history of my role in the development of the Web and W3C, I noted that the Internet not only faciiltates remote collaboration; it also opens the door to crime at a distance. Extortion of the form "say... nice web site you got there; it would be a shame if something happened to it" is a reality. I'm interested in research into how much the Internet can tolerate before we see the tragedy of the commons.

I noted the Proof-of-work proves not to work result by Laurie and Clayton in 2004 as a fairly surprising result based on what looks like fairly straightforward and unsophisticated economic analysis of spam, zombies, etc. Does the humanities research community have expertise in statistics and economics of preserving cultural values such as open communication? (Oh yeah... and I meant to encourage them to look at social/ethical issues around OpenID and distributed authentication, but I completely forgot.)

While HASTAC is somewhat on the leading edge of the humanities community, I'm not sure their scope includes what I'm looking for.

Meanwhile, at the Web Science panel at WWW2007 in Banff, Peter asked "Where are the cultural anthropologists?" I was pleasantly surprised that some of them were there. Again, at Harry Halpin's prompting.

I have been tracking the mercurial project for a couple years now. First just a bookmark under python+scm, then after using hg to code on an airplane about a year later, I was hooked. I helped get the microformats testing effort using mercurial about a year later, and did some noodling on Access control and version control: an over-constrained problem? around that same time.

Yesterday I played host to Matt Mackall as he gave a presentation, The Mercurial SCM, to the W3C Team. In the disucssion that followed, we touched on:

• fractal project organization (touching on PartiaClone and the ForestExtension)
• the toplogy of update flows in a large development system with
  overlapping communities with differentt access rights
• comparisons with Darcs
• hg hosting, large projects, user support

It seems that hg scales to very large projects, as long as they're fairly uniform, but it doesn't support the sort of tangly fractal web of inter-project dependencies that would make it the holy grail of version control systems.

Working with the MIT tabulator students has been such a blast that while I was at U.T. Austin for the research library symposium, I thought I would try to recruit some undergrads there to get into it. Bob Boyer invited me to speak to his PHL313K class on why the heck they should learn logic, and Alan Cline invited me to the Dean's Scholars lunch, which I used to attend when I was at U.T.

To motivate logic in the PHL313K class, I started with their experience with HTML and blogging and explained how the Semantic Web extends the web by looking at links as logical propositions. I used my XML 2005 slides to talk a little bit about web history and web architecture, and then I moved into using hCalendar (and GRDDL, though I left that largely implicit) to address the personal information disaster. This was the first week or so of class and they had just started learning propositional logic, and hadn't even gotten as far as predicate calculus where atomic formulas like those in RDF show up. And none of them had heard of microformats. I promised not to talk for the full hour but then lost track of time and didn't get to the punch line, "so the computer tells you that no, you can't go to both the conference and Mom's birthday party because you can't be in two places at once" until it was time for them to head off to their next class.

One student did stay after to pose a question that is very interesting and important, if only tangentially related to the Semantic Web: with technology advancing so fast, how do you maintain balance in life?

While Boyer said that talk went well, I think I didn't do a very good job of connecting with them; or maybe they just weren't really awake; it was an 8am class after all. At the Dean's Scholars lunch, on the other hand, the students were talking to each other so loudly as they grabbed their sandwiches that Cline had to really work to get the floor to introduce me as a "local boy done good." They responded with a rousing ovation.

Elaine Rich had provided the vital clue for connecting with this audience earlier in the week. She does AI research and had seen TimBL's AAAI talk. While she didn't exactly give the talk four stars overall, she did get enough out of it to realize it would make an interesting application to add to a book that she's writing, where she's trying to give practical examples that motivate automata theory. So after I took a look at what she had written about URIs and RDF and OWL and such, she reminded me that not all the Deans Scholars are studying computer science; but many of them do biology, and I might do well to present the Semantic Web more from the perspective of that user community.

So I used TimBL's Bio-IT slides. They weren't shy when I went too fast with terms like hypertext, and there were a lot of furrowed brows for a while. But when I got to the drug discovery diagram, I said I didn't even know some of these words and asked them which ones they knew. After a chuckle about "drug", one of them explained about SNP, i.e. single nucleotide polymorphism and another told me about OMM and the discussion really got going. I didn't make much more use of Tim's slides. One great question about integrating data about one place from lots of sources prompted me to tempt the demo gods and try the tabulator. The demo gods were not entirely kind; perhaps I should have used the released version rather than the development version. But I think I did give them a feel for it. In answer to "so what is it you're trying to do, exactly?" I gave a two part answer:

1. Recruit some of them to work on the tabulator so that their name might be on the next paper like the SWUI06 paper, Tabulator: Exploring and Analyzing linked data on the Semantic Web.
2. Integrate data accross applications and accross administrative boundaries all over the world, like the Web has done for documents.
   

We touched on the question of local and global consistency, and someone asked if you can reason about disagreement. I said that yes, I had presented a paper in Edinburgh just this May that demonstrated formally a disagreement between several parties

One of the last questions was "So what is computer science research anway?" which I answered by appeal to the DIG mission statement:

The Decentralized Information Group explores technical, institutional and public policy questions necessary to advance the development of global, decentralized information environments.

And I said how cool it is to have somebody in the TAMI project with real-world experience with the privacy act. One student followed up and asked if we have anybody with real legal background in the group, and I pointed him to Danny. He asked me afterward how to get involved, and it turned out that IRC and freenode are known to him, so the #swig channel was in our common neighborhood in cyberspace, even geography would separate us as I headed to the airport to fly home.

technorati tags:Austin, semantic, web

Blogged with Flock

In our PAW and TAMI projects, we're making a lot of progress on the practical aspects of proof exchange: in PAW we're working out the nitty gritty details of making an HTTP client (proxy) and server that exchange proofs, and in TAMI, we're working on user interfaces for audit trails and justifications and on integration with a truth maintenance system.

It doesn't concern me too much that cwm does some crazy stuff when finding proofs; it's the proof checker that I expect to deploy as part of trusted computing bases and the proof language specification that I hope will complete the Semantic Web standards stack.

But N3 proof exchange is no longer a completely hypothetical problem; the first examples of interoperating with InferenceWeb (via a mapping to PML) and with Euler are working. So it's time to take a close look at the proof representation and the proof theory in more detail.

My trip to Austin for a research library symposium at the University of Texas gave me a chance to re-connect with Bob Boyer. A while back, I told him about RDF and asked him about Semantic Web logic issues and he showed me the proof checking part of McCune's Robbins Algebras Are Boolean result:

Proofs found by programs are always questionable. Our approach to this problem is to have the theorem prover construct a detailed proof object and have a very simple program (written in a high-level language) check that the proof object is correct. The proof checking program is simple enough that it can be scrutinized by humans, and formal verification is probably feasible.

In my Jan 2000 notes, that excerpt is followed by...

I offer a 500 brownie-point bounty to anybody who converts it to Java and converts the ()'s in the input format to <>'s.

5 points for perl. ;-)

Bob got me invited to the ACL2 seminar this week; in my presentation, Toward proof exchange in the Semantic Web. I reviewed a bit of Web Architecture and the standardization status of RDF, RDFS, OWL, and SPARQL as background to demonstrating that we're close to collecting that bounty. (Little did I know in 2000 that TimBL would pick up python so that I could avoid Java as well as perl ;-)

Matt Kauffman and company gave all sorts of great feedback on my presentation. I had to go back to the Semantic Web Wave diagram a few times to clarify the boundary between research and standardization:

• RDF is fully standardized/ratified
  
• turtle has the same expressive capability as RDF's XML syntax, but isn't fully ratified, and
• N3 goes beyond the standards in both syntax and expressiveness
  

One of the people there who knew about RDF and OWL and such really encouraged me to get N3/turtle done, since every time he does any Semantic Web advocacy, the RDF/XML syntax is a deal-killer. I tried to show them my work on a turtle bnf, but what I was looking for was in June mailing list discussion, not in my February bnf2turtle breadcrumbs item.

They asked what happens if an identifier is used before it appears in an @forAll directive and I had to admit that I could test what the software does if they wanted to, but I couldn't be sure whether that was by design or not; exactly how quantification and {}s interact in N3 is sort of an open issue, or at least something I'm not quite sure about.

Moore noticed that our conjunction introduction (CI) step doesn't result in a formula whose main connective is conjuction; the conjuction gets pushed inside the quantifiers. It's not wrong, but it's not traditional CI either.

I asked about ACL2's proof format, and they said what goes in an ACL2 "book" is not so much a proof as a sequence of lemmas and such, but Jared was working on Milawa, a simple proof checker that can be extended with new prooftechniques.

I started talking a little after 4pm; different people left at different times, but it wasn't until about 8 that Matt realized he was late for a squash game and headed out.

I went back to visit them in the U.T. tower the next day to follow up on ACL2/N3 connections and Milawa. Matt suggested a translation of N3 quantifiers and {}s into ACL2 that doesn't involve quotation. He offered to guide me as I fleshed it out, but I only got as far as installing lisp and ACL2; I was too tired to get into a coding fugue.

Jared not only gave me some essential installation clues, but for every technical topic I brought up, he printed out two papers showing different approaches. I sure hope I can find time to follow up on at least some of this stuff.

del.icio.us tags:Austin, semantic, web, logic, research

Blogged with Flock

Wow. What a week!

I'm always on the lookout for opportunities to get back to Austin, so I was happy to accept an invitation to this 11 - 12 September symposium, The Research Library in the 21st Century run by University of Texas Libraries:

In today's rapidly changing digital landscape, we are giving serious thought to shaping a strategy for the future of our libraries. Consequently, we are inviting the best minds in the field and representatives from leading institutions to explore the future of the research library and new developments in scholarly communication. While our primary purpose is to inform a strategy for our libraries and collections, we feel that all participants and their institutions will benefit.

I spent the first day getting a feel for this community, where evidently a talk by Clifford Lynch of CNI is a staple. "There is no scholarship without scholarly communication," he said, quoting Courant. He noted that traditionally, publishers disseminate and libraries preserve, but we're shifting to a world where the library helps disseminate and makes decisions on behalf of the whole world about which works to preserve. He said there's a company (I wish I had made a note of the name) that has worked out the price of an endowed web site; at 4% annual return, they figure it at $2500/gigabyte.

James Duderstadt from the University of Michigan told us that the day when the entire contents of the library fits on an iPod (or "a device the size of a football" for other audiences that didn't know about iPods ;-) is not so far off. He said that the University of Michigan started digitizing their 7.8million volumes even before becoming a Google Book Search library partner. They initially estimated it would take 10 years, but the current estimate is 6 years and falling. He said that yes, there are copyright issues and other legal challenges, and he wouldn't be suprised to end up in court over it; he had done that before. Even the sakai project might face litigation. What got the most attention, I think, was when he relayed first-hand experience from the Spellings Commission on the Future of Higher Education; their report is available to those that know where to look, though it is not due for official release until September 26.

He also talked about virtual organizations, i.e. groups of researchers from universities all over, and even the "meta university," with no geographical boundaries at all. That sort of thing fueled my remarks for the Challenges of Access and Preservation panel on the second day. I noted that my job is all about virtual organizations, and if the value of research libraries is connected to recruiting good people, you should keep in mind the fact that "get together and go crazy" events like football games are a big part of building trust and loyalty.

Kevin Guthrie, President of ITHAKA, made a good point that starting new things is usually easier than changing old things, which was exactly what I was thinking when President Powers spoke of "preserving our investment" in libraries in his opening address. U.T. invested $650M in libraries since 1963. That's not counting bricks and mortar; that's special collections, journal subscriptions, etc.

My point that following links is 96% reliable sparked an interesting conversation; it was misunderstood as "96% of web sites are persistent" and then "96% of links persist"; when I clarified that it's 96% of attempts to follow links that succeed, and this is because most attempts to follow links are from one popular resource to another, we had an interesting discussion of ephemera vs. the scholarly record and which parts need what sort of attention and what sort of policies. The main example was that 99% of political websites about the California run-off election went offline right after the election. My main point was: for the scholarly record, HTTP/DNS is as good as it gets for the forseeable future; don't throw up your hands at the 4% and wait for some new technology; apply your expertise of curation and organizational change to the existing technologies.

In fact, I didn't really get beyond URIs and basic web architecture in my remarks. I had prepared some points about the Semantic Web, but I didn't have time for them in my opening statement and they didn't come up much later in the conversation, except when Ann Wolpert, Director of Libraries at MIT, brough up DSPACE a bit.

Betsy Wilson of the University of Washington suggested that collaboration would be the hallmark of the library of the future. I echoed that back in the wrap-up session referring to library science as the "interdisciplinary discipline"; I didn't think I was making that up (and a google search confirms I did not), but it seemed to be new to this audience.

By the end of the event I was pretty much up to speed on the conversation; but on the first day, I felt a little out of place and when I saw the sound engineer getting things ready, I mentioned to him that I had a little experience using and selling that sort of equipment. It turned out that he's George Geranios, sound man for bands like Blue Oyster Cult for about 30 years. We had a great conversation on digital media standards and record companies. I'm glad I sat next to David Seaman of the DLF at lunch; we had a mutual colleague in Michael Sperberg-McQueen. I asked him about IFLA, one of the few acronyms from the conversation that I recognized; he helped me understand that IFLA conferences are relevant, but they're about libraries in general, and the research library community is not the same. And Andrew Dillon got me up to speed on all sorts of things and made the panel I was on fun and pretty relaxed.

Fred Heath made an oblique reference to a New York Times article about moving most of the books out of the U.T. undergraduate library as if everyone knew, but it was news to me. Later in the week I caught up with Ben Kuipers; we didn't have time for my technical agenda of linked data and access limited logic, but we did discover that both of us were a bit concerned with the fragility of civilization as we know it and the value of books over DVDs if there's no reliable electricity.

The speakers comments at the symposium were recorded; there's some chance that edited transcripts will appear in a special issue of a journal. Stay tuned for that. And stay tuned for more breadcrumbs items on talks I gave later in the week where I did get beyond the basic http/DNS/URI layer of Semantic Web Archtiecture.

tags:Austin, URI, Web Architecture

Here comes (some of) the TAG
Originally uploaded by Norm Walsh.

The last item on the agenda of the TAG meeting in France was "Reviewing what we have learned during a full week of meetings". I proposed that we do it on the beach, and it carried.

By then, the network woes of Monday and Tuesday had largely faded from memory.

I was on two of the plenary day panels. Tantek reports on one of them: Microformats voted best session at W3C Technical Plenary Day!. My presentation in that panel was on GRDDL and microformats. Jim Melton followed with his SPARQL/SQL/XQuery talk. Between the two of them, Noah Mendelsohn said he thought the Semantic Web might just be turning a corner.

My other panel presentation was Feedback loops and formal systems where I talked about UML and OWL after touching on contrast between symbolic approaches like the Semantic Web and statistical approaches like pagerank. Folksonomies are an interesting mixture of both, I suppose. Alistair took me to task for being sloppy with the term "chaotic system"; he's quiet right that complex system is the more appropriate description of the Web.

The TAG discussion of that session started with jokes about how formal systems is soporific enough without putting it right after a big French lunch. TimBL mentioned the scheme denotational semantics, and TV said that Jonathan Rees is now at Creative Commons. News to me. I spent many, many hours poring over his scheme48 code a few years back. I don't think I knew where the name came from until today: Within 48 hours we had designed and implemented a working Scheme, including read, write, byte code compiler, byte code interpreter, garbage collector, and initialization logic.

The SemWeb IG meeting on Thursday was full of fun lightning talks and cool hacks. I led a GRDDL discussion that went well, I think. The SPARQL calendar demo rocked. Great last-minute coding, Lee and Elias!

There and back again

On the return leg of my itinerary, the captain announced the cruising altitude, as usual, and then added ... which means you'll spend most of today 6 miles above the earth.

My travel checklist worked pretty well, with a few exceptions. The postcard thing isn't a habit yet. I forgot a paperback book; that was OK since I slept quite a bit on the way over and I got into the coding zone on the way back more about that later, I hope.

Other Reflections

See also reflections by:

• Elias Torres
• Norm Walsh

... and stay tuned for something from

• Dave Orchard
• TV Raman

See also: Flickr photo group, NCE bookmarks