Re: Semantic Bleachers: was Re: Afghanistan War Diary as topic map in Maiana

Andrew,

On Mon, 2010-11-01 at 06:32 +0000, Andrew S. Townley wrote:
> Hi Patrick,
> 
> On 1 Nov 2010, at 1:11 AM, Patrick Durusau wrote:
> > 
> > PS: I think assigning properties to subjects and then saying on what
> > basis we think they are the same as other subjects avoids the pitfalls
> > of the OWL sameAs which has no properties nor any way for a user to
> > indicate on what basis they claimed "sameAs." 
> 
> 
> This point is so absolutely critical so that people understand the basis on which an equality assertion is being made.  I've long held that equality is nothing more than having a particular set of properties the same, even if those are a subset of properties and the equality is only intended to exist in a limited context.  It's on the basis of property values, not magic ids, that define whether or not a given proxy (or topic) should be claimed to the same subject in a given context.
> 

Actually whether the properties and their values are the "same," is a
decision I would leave up to the legend designer. 

That is there could be a rule that says:

If fullname = "Patrick Durusau" and SSN = "***-**-****", same subject,
so that merging would happen even if those properties were in separate
containers. 

I think the creative fashioning of merging rules, with boundaries for
their application is largely unexplored territory. 

We would benefit from a very robust set of comparison operators.  

> I think you alluded to this the other day with some of your work, but I think that the idea behind what Manina is doing, what I understood was possible with what you have and the way that my implementation handles merging on a conditional rather than absolute basis illustrates that there's still work to be done in this area of the topic maps specifications.  Maybe some implementations take too literal a view on the whole XTM/TMDM merging requirements, but it makes a big deal if you define "equality" on the basis of property values, merge and then one or more of those property values change.
> 

Well, those are separate questions:

a. How to merge on something in addition to the standard TMDM basis?

b. What happens if after merging a value changes? (unexplored so far as
I know, but good question)

> How do other implementations handle this scenario?  To me the answer is key to dealing with large, somewhat ambiguous data sets like the Afghan one that stated the discussion and allowing the humans using them to derive real value from them--regardless what encoding and representation they start or finish in.
> 

I don't know.

My personal interest is in functional topic maps that display "merged"
information as it is requested.

In that case, the answer to your question of what happens if a value
changes after merging is likely to be different from file oriented
systems. 

> Well-defined conversions are easy, but what isn't easy is doing something useful and meaningful with the output of those conversions.  On this point, I think the majority of us agree. :)
> 

Very true!

Hope you are at the start of a great week!

Patrick


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