What is this Expert Location thing?

Maybe this has happened to you before: You are one of those fabled 'knowledge workers'. You realize that you really need to know about a certain subject. We'll call that subject FooBar. You look in your corporate knowledge base (you do have one, right?) and you find a document there with 'FooBar' in the keywords list. Unfortunately, you know nothing about FooBar, so you can't really tell if this is the latest thinking on FooBar, or what this whole FooBar thing is about, what all these FooBar buzzwords really mean. Maybe you just need to talk to the person who wrote this document and learn more. What you need is a FooBar Expert.

But how do you find that expert? Theres been a lot of ink spilled on that very question, but I'm not sure anyone has found the holy grail of expert location. I've been thinking about the subject myself (heck, just the other week someone accused me of being an expert on expert location!) . And I figure if fingers are getting pointed, I should share my thoughts on the subject.

So what makes an expert? There are a lot of definitions of “expert” out there, but I like this one: “An expert is someone widely recognized as a reliable source of knowledge, technique, or skill whose judgment is accorded authority and status by the public or their peers.” I like that definition because some key ideas – wide recognition, reliability, trust. I think each of those concepts is worthy of its own discussion, so I'll just start at the top - recognition. How DO we find that FooBar expert?

For computers, recognition is done through some form of people tagging. While there is certainly a lot to be said on how humans tag expertise in their head, for now we'll stick to how computers can aid in finding experts. If you think about it, there are a couple of ways for an expert location system to tag experts: Creator (Self) tagging, Expert Tagging (i.e. A librarian), Machine Tagging (i.e. Entity Extraction), Social Tagging (i.e. Folksonomy, group, or "Peer" tagging).

Each type of tagging has its pros and cons:

• Self tagging isn't a bad approach necessarily, but the typical definition of expert tends to be "a widely recognized and trusted source of knowledge"; so being self-tagged instead of peer-tagged has its flaws (hubris!). On the other hand, no one else tends to know what you know better than yourself.
• Expert Tagging comes from the library science way of defining things. The benefit is (one hopes) an independant certification of what one knows. Expert tagging can also come implicitlly in a corporate environment from organizational structure. If you are the lead or even a member of the FooBar group, you're assumed to be a FooBar expert.
• Machine Tagging is an emerging concept, but not a new one. Intelligence analysts (aka spies) have been using machine-based tagging to connect people with what they know through all sorts of intelligent (pun intended) algorithms. The basic concept is that you can pull key words (usually called 'entities') from text (newspapers, audio transcripts, overhead phone calls, and so forth) to connect the content of what is being said to the person doing the talking, the person they are talking to, and the person they are talking about. Its a great approach for finding a needle in the expertise haystack, and as a result organizations spend a lot of money on tools that find quality connections. However, it assume you have a lot of hay (and a lot of dough) to work with.
• Social Tagging is probably the most common "non-computer-aided" way to tag an expert. Back to my definition - an expert is someone widely recognized. Social tagging the traditional way comes from professional groups. First, you have the groups that certify expertise. This can be anything from the American Bar (lawyers) to the Institute of Electrical and Electronics Engineers (IEEE - Engineers, naturally).
  In academia, you also find a ranking system - citations. The value of papers written on subjects and ones expertise credentials are boosted by the number of your peers who cite your work as a source for theirs. Those who are considered experts in their field are those whose work is more frequently cited (the same is arguable true of blogs).
  Expertise in other fields can also be through informal referral networks - especially in fields where people don't write or obtain certifications for a living. Using general contracting and contruction as an example, people maintain personal networks and evaluate expertise based on performance. All plumbers are certified through a variety of trade guilds and professional groups. But that may not be the only measure of expertise. One might be considered an expert plumbler if 9 out of 10 general contractors recommend you to fix leaky pipes - and in many fields the personal trust outweighs the formal titles.
  Is there a weakness to social tagging? Of course - first it requires people to contribute to the classification of other people (People are too lzy to tag themselves, will they really tag others?); second it assumes that others are a good judge of what it is you know.

There is a lot more to be said on the subject, but thats a start. After all, its not like I'm an expert on this.