[RDF] Version handling

[Stefan Andersson]

Warning: Rant-in-the-night

> Versionhandling comes partly by itself.
> 
> Each model is a group of statements from a specific agent at a
> specific time. The time and agent gets stored in the model metadata.
> 
> If the same agent (person) updates some data, that is done in a new
> model.  A presentation of a resource propertis could just display
> propertes from a specific agent or all later data from later than a
> specific date.
> 
> But how do we say that one statement should replace another statement?
> Or that a specific statement or group of them should be deleted?
> 
> What would be a good way of handling this?

I'd say there is no 'good' way of handling it. Either you go the full
nine yards, and implement a system capable of handling true
(hyperdimensional) context, which probably would be humongously big and
slow, or you have to cut it down. And cutting down necessarily means
letting out.

In 'the real world' we do remember stuff that an agent has said before
even if that agent says something else now. Is the discrepansies between
now and then too wide, or if we encounter them too often, we will have
to downgrade our trust in that source. Once more trust. Trust is key.

My point being that every statement is separated in time and space from
every other statement. The idea that two statements are 'the same' is a
connection done on the idea plane - thus one would need a layer of root
data, and another interconnecting layer of 'sameness' or 'class'. That
is, 'instance' has to be a recursive in the same way as 'class' is. Once
more - class vs instance.

Actually - one could say 'version' roughly means 'sufficiently
equivalent', that is, 'all those instances could fill roughly the same
function, but with small, maybe critical, differences'.
Sameness/Differentness as a vector... hmm. With increasing time one
supposes increased accumulation of experience and inference, thus the
versions ordered temporally represents increasing experience and
inference... but where is the breaking points? Where is the 'this is one
version, and now it has changed enough that we may call it another'? I
see the analogy to the 'what is a model, and what is not'-question.
Internal concistency seems like a good measure...

* yawwn *

'night!
/Stefan