RE: Re[1] DAML-ONT: the case for closedness

Lewis Hart:
>A search engine, for example, must keep track of what is
>believed where/by whom. Keeping track of this could be tedious.
>If a search engine imports every ontology it comes across, the search
>engine's own, internal ontology will eventually be quite a mess. Rather,
>the engine needs to build articulations among it's internal ontology and
>the external ones on the web. Essentially, meta facts about what is believed
>by external systems, with reference to its own beliefs. This will allow
>a representation of a set of sites that believe daml:Thing isa ec:Computer
>without the search engine believing it internally.
>The good things about this are:
>1) Anybody can still say anything.
>2) There is no central authority.
>  2a) Authorities will arise out of usage.
>3) The scope of bad a ontology is limited.
>  3a) Search engines can cut them off at the root if desired.
>4) Information can still be found.
>The Bad things are:
>1) Systems will have to delineate between what it knows about
>   and what it believes.
>2) Keeping track of this could be resource intense.
>3) Some sites will think everything is a computer.

I agree this is the right vision. As long as every assertion can be 
'traced' to its source, then it will be possible to disentangle who 
has been saying what about who. However, if we allow inferences to be 
drawn, stored and then retrieved, things could get a little more 
complicated.  It might be that something that bad: said allows one to 
infer something which does not itself refer to anything bad#.  To 
keep track of things properly then would require not just tracking 
the URI's in the sentence being examined, but also those in every 
sentence that was used to derive that sentence. This means that 
(barring some new security mechanism) one should never archive a bare 
conclusion, but only archive a conclusion together with its 
derivation (logical proof).

This isnt an issue yet, but I think it will be very soon.

Pat Hayes

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Received on Monday, 23 October 2000 16:50:40 UTC