Tags: RDFa



Open Tech 2008

Open Tech was fun. It was like a more structured version of BarCamp: the schedule was planned in advance and there was a nominal entrance fee of £5 but apart from that, it was pretty much OpenCamp. Most of the talks were twenty minutes long, grouped into hour-long thematically linked trilogies.

Things kicked off with a three way attack by Kim Plowright, Simon Wardley and Matt Webb. I particularly enjoyed Matt’s stroll down the memory lane of the birth of cybernetics. Alas, the fact that I stayed to enjoy this history lesson meant that I missed David Hayes’s introduction to Edenbee. But I did stick around for the next set of environment-related talks including a demo of the Wattson from DIY Kyoto and the always-excellent Gavin Starks of AMEE fame.

After a pub lunch spent being entertained by Ewan Spence’s thoroughly researched plan for a muppet remake of Star Wars, I made it back in time for a well-connected burst of talks from Simon, Gavin and Paul. Simon pimped OpenID. Gavin delivered a healthy dose of perspective from the h’internet. Paul ranted about the technologies depicted in his wonderful illustration entitled The Web is Agreement.

I made sure to catch the state of the nation address from Open Street Map. It was, as expected, inspiring. It’s quite amazing how far the project has come since the last Open Tech in 2005. Hearing about the wealth of data available gave me the kick up the arse to update the dConstruct location page to use Open Street Map tiles. It turned out to be a simple process involving the addition of just a few more lines of JavaScript.

My talk at Open Tech was a reprise of my XTech presentation, Creating Portable Social Networks With Microformats although the title on the schedule was Publishing With Microformats. I figured that the Open Tech audience would be fairly advanced so I decided against my original plan of doing an introductory level talk. The social network portability angle also tied in with quite a few other talks on the day.

I shared my slot with Jeni Tennison who gave a hands-on look at RDFa at the London Gazette. The two talks complemented each other well… just like microformats and RDFa. As Jeni said, microformats are great for doing the easy stuff—the low-hanging fruit—and deliberately avoid more complex data structures: they hit 80% of the use cases with 20% of the effort. RDFa, on the other hand, can handle greater complexity but with a higher learning curve. RDFa covers the other 20% of use cases but with 80% effort. Jeni’s case study was the perfect example. Whereas as I had been showing the simple patterns of user profiles and relationships on social networks (easily encoded with and ), she was dealing with a very specific data set that required its own ontology.

I was chatting with Dan at the start of Open Tech about this relationship. We’re both pretty fed up with the technologies being set up as somehow being rivals. Personally, I’m very happy that RDFa covers the kind of data structures that microformats doesn’t touch. When someone comes to the microformats community with an idea for a complex data format, it’s handy to have another technology to point them to. If you’re dealing with simple, common structures that have aggregate benefit like contact details, events and reviews, microformats are the perfect fit. But if you’re dealing with more complex structures—and I’m thinking here about museum collections, libraries and laboratories—chances are that some flavour of is going to be more suitable.

Jeni and I briefly discussed whether we should set up our talks as a kind of mock battle. But that kind of rivalry, even when it’s done in a jokey fashion, is unnecessary and frankly, more than a little bit dispiriting. It’s more constructive to talk about real-world use cases. On that basis, I think our Open Tech presentations hit the right note.

Why You Should Have a Web Site

The enigmatic is at XTech to tell us Why you should have a Web site: it’s the law! (and other Web 3.0 issues). God, I hope he’s using Web 3.0 ironically.

Steven has heard many predictions in his time: that we will never have LCD screens, that digital photography could never replace film, etc. But the one he wants to talk about is Moore’s Law. People have been seeing that it hasn’t got long to go since 1977. Steven is going to assume that Moore’s Law is not going to go away in his lifetime.

In the 1980s the most powerful computers were the Crays. People used to say One day we will all have a Cray on our desk. In fact most laptops are about 120 Craysworth and mobile phones are about 35 Craysworth.

There is actually an LED correlation to Moore’s Law (brighter and cheaper faster). Steven predicts that within our lifetime all lighting will be LCDs.

Bandwidth follows a similar trend. Jakob Nielsen likes to claim this law; that bandwidth will double every year. In fact the timescale is closer to 10.5 months.

Following on from Moore’s and Nielsen’s laws, there’s Metcalfe’s Law: the value of a network is proportional to the square of the number of nodes. This is why it’s really good that there is only one email network and bad that there are so many instant messenger networks.

Let’s define the term Web 2.0 using Tim O’Reilly’s definition: sites that gain value by their users adding data to them. Note that these kinds of sites existed before the term was coined. There are some dangers to Web 2.0. When you contribute data to a web site, you are locking yourself in. You are making a commitment just like when you commit to a data format. This was actually one of the justifications for XML — data portability. But there are no standard ways of getting your data out of one Web 2.0 site and into another. What if you want to move your photos from one website to another? How do you choose which social networking sites to commit to? What about when a Web 2.0 site dies? This happened with MP3.com and Stage6. Or what about if your account gets closed down? There are documented cases of people whose Google accounts were hacked so those accounts were subsequently shut down — they lost all their data.

These are examples of Metcalfe’s law in action. What should really happen is that you keep all your data on your website and then aggregators can distribute it across the Web. Most people won’t want to write all the angle brackets but software should enable you to do this.

What do we need to realize this vision? First and foremost, we need machine-readable pages so that aggregators can identify and extract data. They can then create the added value by joining up all the data that is spread across the whole Web. Steven now pimps RDFa. It’s like microformats but it will invalidate your markup.

Once you have machine-readable semantics, a browser can do a lot more with the data. If a browser can identify something as an event, it can offer to add it to your calendar, show it on a map, look up flights and so on. (At this point, I really have to wonder… why do the RDFa examples always involve contact details or events? These are the very things that are more easily solved with microformats. If the whole point of RDFa is that it’s more extensible than microformats, then show some examples of that instead of showing examples that apply equally well to hCalendar or hCard)

So rather than putting all your data on other people’s Web sites, put all your data on your Web site and then you get the full Metcalfe value. But where can you store all this stuff? Steven is rather charmed by routers that double up as web servers, complete with FTP. For a personal site, you don’t need that much power and bandwidth. In any case, just look at all the power and bandwidth we do have.

To summarise, Web 2.0 is damaging to the Web. It divides the Web into topical sub-webs. With machine-readable pages, we don’t need those separate sites. We can reclaim our data and still get the value. Web 3.0 sites will aggregate your data (Oh God, he is using the term unironically).

Questions? Hell, yeah!

Kellan kicks off. Flickr is one of the world’s largest providers of RDFa. He also maintains his own site. Even he had to deal with open source software that got abandoned; he had to hack to ensure that his data survived. How do we stop that happening? Steven says we need agreed data formats like RDFa. So, Kellan says, first we have to decide on formats, then we have to build the software and then we have to build the aggregators? Yes, says Steven.

Dan says that Web 2.0 sites like Flickr add the social value that you just don’t get from building a site yourself. Steven points to MP3.com as a counter-example. Okay, says Dan, there are bad sites. Simon interjects, didn’t Flickr build their API to provide reassurance to people that they could get their data out? Not quite, says Kellan, it was created so that they could build the site in the first place.

Someone says they are having trouble envisioning Steven’s vision. Steven says I’m not saying there won’t be a Flickr — they’ll just be based on aggregation.

Someone else says that far from being worried about losing their data on Flickr, they use Flickr for backup. They can suck down their data at regular intervals (having written a script on hearing of the Microsoft bid on Yahoo). But what Flickr owns is the URI space.

Gavin Starks asks about the metrics of energy usage increases. No, it drops, says Steven.

Ian says that Steven hit on a bug in social websites: people never read the terms of service. If we encouraged best practices in EULAs we could avoid worst-case scenarios.

Someone else says that our focusing on Flickr is missing the point of Steven’s presentation.

Someone else agrees. The issue here is where the normative copy of your data exists. So instead of the normative copy living on Flickr, it lives on your own server. Flickr can still have a copy though. Steven nods his head. He says that the point is that it should be easy to move data around.

Time’s up. That was certainly a provocative and contentious talk for this crowd.