Monday, January 28, 2008

Metadata interoperability

I'm not especially handy. (Get up, those of you who just fell on the floor laughing at the understatement of the century. Stop it. Right now. I know who you are.) Inspired by a recent minor home repair (which would probably be a trivial repair for you normal folks!) involving a screwdriver (flathead, if you were wondering, I'm not quite that inept), I've been thinking about how to explain metadata interoperability in terms of tools.

I've long held that interoperability by prescribing a single way of doing things is unsustainable, even at a relatively small scale, and it seems to me those sets of many-sized gadgets can show us a path forward. Wrenches, bolts, sockets and the like are not all the same. Rather, a bolt is chosen based on what it needs to do - what functions it needs to support and the environment in which it needs to fit. The same is true for descriptive metadata standards. The ones used for a specific class of materials need to both match well with the materials themselves and are supported in the institutional environment.

On the other side, how to deal with a bolt may not be immediately obvious, but it's not all that hard to figure it out. There are many options for what size socket wrench would be needed to tighten or loosen it. It would be nice if the bolt clearly stated what size it was, and this happens in some cases but certainly not in the majority. The wrench needed might be of the type measured in inches or the type measured in millimeters. We can consider these akin to the different approaches to description taken by libraries and archives. A practiced eye can examine the bolt and guess at the right size wrench to try. They'll likely get close, maybe with one or two mis-steps. With trial and error, a novice can find the right wrench as well. I believe the same is true for a system using metadata from an outside source - a skilled human can tell a lot about how best to use it from a quick glance, and trying various tactics out on it will inform how well various choices work for both an expert and a novice. With time and expertise we can transfer some of these evaluations to a system rather than a human (we can do some of this now; for example determining which metadata format from a predefined list is in use can be easily automated), but the process is still the same.

The point as I see it is that for these types of tools there are many options, but each of them are well-defined and well-documented. The same is true for metadata. As we gain more experience, we work towards defining various approaches that work for a given class of materials in a given environment. We then don't need to re-evaluate everything every time we start something new; we can refer to existing knowledge to see that in this case that approach has proven to be useful.

Maybe this analogy fails once you look closer (especially on the tool side - what's here pretty much represents my entire understanding of those types of things), but, like any analogy, it's bound to break down at some point of examination. But I've been pondering a bit and for now I still think it's useful. Feel free to argue with me, though!


Anonymous said...

Although bolts may be different sizes, require different tools to tighten/loosen, etc. almost ALL bolts (except certain security bolts) are righty tighty, lefty loosey.

That seems like a kind of interoperability feature that would be useful to have in metadata.

But a bolt is a very simple thing and pretty easy to figure out. Figuring out how to put the whole machine together is another story altogether.

Having done some work looking at web usability questions I've been wondering for a while why these concepts have not made it out to other areas. Have we ever discussed "metadata usability?" or metadata documentation usability?

Maybe somone needs to get Don Norman to come talk to us.

And...isn't this kind of interoperability part of the argument behind the semantic web?

Owen said...

But how often do you end up using a screw because it's the one you have to hand, rather than because after careful analysis of the problem you've decided that this is the particular screw you should use?

Also, making a mistake about the right tool can cause real problems - ever used the wrong size cross-head and ended up ruining the screw and having to drill out the remains?

As Richard says, some basics also would be good to agree on. To perhaps labour the analogy a bit, you could argue that the rest of the world has moved on to using Allan keys of different sizes (lets say XML and HTML) for information, while libraries keep on using screws. You can argue that screws do the job, and have done for years, and there's nothing wrong with them, but if you want to put together your latest IKEA purchase a screwdriver just ain't going to cut it.

I feel the metaphor is showing the strain now, but some useful areas for discussion I think.

Anonymous said...

I really like the notion of metadata interoperability, and especially your tool analogy.

I'm a little bit fuzzy on the analogy though. Are you saying that tools are to assembled things as metadata formats are to descriptions? Or in SAT lingo:

tools:assembled_things :: metadata_formats:descriptions

Can you explore the analogy a little more?

Also, I like Richard's point about the role of semantic web technology. I think that RDF (specifically the notion of the triple) could be seen as playing the part that a measurement system plays in tool use (sizes of nuts, bolts, wrenches, screw drivers, etc).

The triple allows a statement to be made about resources, which are identified with URIs. It provides a framework wherein different vocabularies can be used. I prefer to think of vocabularies for describing things rather than metadata formats, but it comes down to the same thing.

So I guess I'm thinking more along the lines of:

tools:assembled_things :: vocabularies:descriptions

I totally agree with your main point that there will be no-single metadata format, or vocabulary for describing things. The reality is that there will be many vocabularies, some more popular than others, some specifically tuned to a particular task. The library metadata world needs technical solutions that encourage the use, inter-use, and cross-breeding of vocabularies. This is where the simple notion of the RDF triple excels.

Maybe I'm stretching the analogy beyond recognition now. Thanks for writing about this :-)