A DTD for Life Redux

Around 5 years ago I began working intensively with XML and XSLT at the company I was then working for. My main task was to write XSLT stylesheets to turn book and journal XML into online products so that anyone in the world could access them via the internet (providing they had a subscription for the product). We were working with a really comprehensive DTD which seemed to capture just about everything you could need for storing information about books and journals, and it was really fascinating to figure out how XSLT could be used to pick out all the bits of metadata stored in the XML and be made to repurpose it into interesting pages.

I got really fascinated by the XML/XSLT combination when I first swapped stylesheets from one journal to another in order to figure out how they worked; there was the data I’d been used to seeing in one incarnation rendered in another. If you can’t fathom what I’m talking about, imagine we have two projects, A & B. Their content is stored in XML, and they both use the same DTD, so their XML is structured in the same way and provides the same information. They both have XSLT stylesheets too, which provide “look and feel” (they provide a whole lot more, but I’m keeping this simple). Imagine project A is about tomatoes, so it’s mostly red, and project B is about the ocean, so it’s mostly blue. If you swap the stylesheet from project A to project B, you get the content of project B but in the look and feel of project A; in this case, a project about the ocean rendered as if it was all about tomatoes.

Normally you would not want to do this.

But it gave me an idea. What if, instead of capturing book, or journal, or inventory data, you could actually capture all of your daily life in XML? Moreover, what if you then wrote an XSLT that recreated your experience of it? Just as the publishing XML captures a print publication, and its XSLT recreates it online for sharing, you could capture your life and then put it online for others to explore (already this is going beyond the scope of webpages and technology that we’re familiar with today, but stick with me). What would be exciting about this is releasing the DTD to the world, sharing other people’s lives, and even “experiencing” them by transforming their life XML with your personal stylesheet. You could experience life as an African, or a Greenlander, or a cleaner as long as they used the same DTD. Or, you could even apply their stylesheet to your own XML.

It was all very exciting, and potentially very funny. I imagined XML with tags like this

<?xml version="1.0" encoding="iso-8859-1" ?>
<life started="01011961" owner="John Zap">
<time type="day" date="10112009" timeofwriting="0952"/>
<place type="building" name="home">
<narration>Okay...My cellphone alarm woke me up at <timestamp time="0715">7.15</timestamp>.  I snoozed until 
<timestamp time="0730">half seven</timestamp>.</narration>  
<narration>I got up, went into the <place type="room" name="bathroom">bathroom</place>, ran the bath, 
and got back into <place type="room" name="bedroom">bed
</place> until <timestamp time="0745">7.45</timestamp> whilst listening to <URI>Radio 4</URI>.  I had a bath 
and got out at <timestamp time="0745">8.15</timestamp>.  
I went downstairs and had <meal type="mainmeal" name="breakfast">breakfast
</meal> in the <place type="room" name="bathroom">kitchen</place> - muesli and coffee.  
After that I went back upstairs, changed into my cycling clothes, packed my work 
clothes, brushed my teeth and went back downstairs.  
I put on my coat, loaded up my bike, wheeled it out of the house, locked up and set off for work.</narration></place>
<place type="location" name="outside"><narration>I cycled into town.</narration></place>
<place type="building" name="work"><narration>At work I entered the premises and locked my bike.  I went into the
corridor, up the stairs, and into my office.  I dumped my bag on the floor,
took out my office clothes and went into the toilet to change.  I came back
into the office, put away my cycling clothes, and sat down at the computer.</narration></place>


and the complexity only growing and growing as more and more tags were needed to capture more and more information about daily life. And then…I realised two things.

1. where was I going to get this data from in order to even tag it?
2. surely this could all be used for the most terrible purposes if it fell into the wrong hands?

I saw the first thing as a bit of a stumbling block, but remained hopeful that something fabulous and relatively easy to use would pop up soon enough to allow all of this. It would just be a matter of someone writing up a clever enough application to allow everyone to write up their life and tag it as needed. Once you got the hang of things most stuff would be recognised automatically by the clever application and done without you even knowing about it.

The second thing bothered me a lot though. After all, if this was an exciting concept, you would want to capture as much of the little things about your life which made it unique. But might also be the most personal parts of your life too, and maybe not the sort of things you really ought to be sharing on the internet.

I’ve toyed with the idea on and off since then anyway as a concept, but recently I am wondering if this isn’t going to arrive all by itself. I attended a lecture by Sir Tim Berners-Lee about the semantic web and it seems lots of other people have been thinking about things like this too. The semantic web is going to be a web of shared data, which is all very exciting, and it seems to offer a way to share this sort of thing.

But the question of how to tag your life still seems too big to grasp. Unless, that is, you forget all about doing it yourself and let some of the new fangled happenings in modern life help you out. You could add up where you’ve been from data from your Oyster card or number plate recognition cameras. Shopping loyalty cards will probably let you compute what you consumed…but then aren’t Oyster cards, trafficmaster, clubcard and others all doing bits of this anyway? If you think about joining it all together then suddenly you’re into a world of TMI and targeted marketing (not to mention profiling of any manner of sorts). Looking at it from that perspective…it doesn’t seem so cool any more.

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