Re: Temporal validitity of subject indicators?

Hi Folks,

On 8 May 2011, at 8:18 PM, Aki Kivelä wrote:

> 
> Hi Robert et al,
> 
> 8.5.2011 19:49, Robert Cerny kirjoitti:
>> The mess is not caused by a merge operation, the mess is caused because a person reuses but misunderstands a (foreign) subject identifier and attaches statements to a topic which they actually do not belong to. Once both interpretations reach the Topic Maps ecosystem (great term, Andrew!), the damage is done.
> 
> Well, doesn't that really resemble the way language evolves. Once I use a word (shared subject identifier) to refer something slightly different to it's common meaning, people (probably) still understand me and can decide whether my identifier was a mistake, a dialect-word, a joke or had a special tone. Or maybe I just have a hidden (political) agenda and want you to focus to something I want. Somehow I am ready to believe that the usage of identifiers is the most important way of defining subjects behind them. And usage refers here the usage in actual topic maps. Thus, speaking about damage in context of using words (shared subject identifiers) is a very strong expression. Now, throw me a stone :)


I agree with Aki here about the evolution of an understanding not precluding you from using certain terms (or references) to illustrate what you mean.  This is a natural evolution that mirrors the way humans learn.  That isn't really the problem I was raising.

Given that subject indicators can be either formal or informal, at some stage you may decide that you just have to pick something that's a "good enough" identity assertion so that you can ensure that other references in external, big, ugly, real data actually get resolved to the same subject you have in your map.  The problem is that it doesn't always make sense to define your own subject indicator because yours isn't going to be any better than the "unofficial" ones you can already find externally.

Hypothetically, let's say you're defining a topic for "Bob's Garage" and you know that Bob's been in business for 20 years with the same telephone number.  A perfectly good choice for a subject indicator might be his website, http://bobsgarage.com or even his telephone number (via RFC2806), tel:+19135551234.  You know that these might have the added advantage of appearing near any other references to Bob's Garage so you pick one or both.

Fast forward to time t+n, and Bob's goes out of business, the hosting company redirects bobsgarage.com to a link farm/advertising page and Bob's phone number gets reassigned to something else.  The problem is that your topic map (authors and users) don't really have any idea that this has happened, so they get new data with these references, but the references now indicate different subjects.  At time t+n+1, someone discovers that the subject indicator is no longer valid and needs to update the map.  You might also just happen to have some old data around that needs to either be referenced or used to rebuild the map.  Some of that "old data" may also be in the form of serialized topic maps.

What do you do?

Ideally, it would be great to have a way to bound the periods of validity for a subject indicator to a given subject.  While the software may not understand this distinction, at least the humans would.  Either way, it gets kinda messy.

Cheers,

ast
--
Andrew S. Townley <[email protected]>
http://atownley.org