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Re: Issue-114

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Tue, 1 Jul 2008 08:02:09 +0100
Message-Id: <CF9789A6-45D8-40F0-AD85-9A4DDBB549F5@cs.man.ac.uk>
Cc: OWL Working Group WG <public-owl-wg@w3.org>
To: Alan Ruttenberg <alanruttenberg@gmail.com>

On Jun 30, 2008, at 11:20 PM, Alan Ruttenberg wrote:

> On Jun 30, 2008, at 5:31 PM, Bijan Parsia wrote:
>
>> On Jun 30, 2008, at 6:59 PM, Alan Ruttenberg wrote:
>>
>>> After discussion with Michael, we agreed to narrow this issue as  
>>> follows: We propose that the only punning in OWL is against  
>>> individuals - that is, anything named in OWL can have an  
>>> individual with the same (punned name).
>>>
>>> This corresponds to what I believe is the commonly requested  
>>> case, and simplifies the current situation in which we have  
>>> narrow restrictions on certain forms of punning - no object/data  
>>> property punning, no class/datatype punning.
>>
>> This is a very tendentious reading of "simplifies". It's just as  
>> sensible, if not more so, to say that this *complicates* the  
>> picture because it unmotivatedly adds restrictions that are not  
>> necessary by any standard. The simplest would be pun everything or  
>> pun nothing. In practice, punning more seems to be less of a  
>> burden than punning less.
>
> There are two points of view on this (at least). One relates to the  
> complexity of users understanding the implications of punning. I  
> will argue that punning individuals to anything is natural and easy  
> to understand, which other forms of punning are not.

I hope you include the consideration of understanding why a document  
is rejected by a syntax checker. In my experience, that's the largest  
bar.

> I don't find it compelling to cite OWL full as a way of  
> understanding property/class punning

Ok, then you discount your appeal to hilog semantics? Those *are*  
hard to work with in the context of e.g., disjunction.

> - In general we have found OWL Full to have confusing semantics,

My point is that this is a case where the semantics are clear  
(indeed, uniform), and there is pointless deviation. We've already  
seen in the case of property/object punning that this syntactic  
deviation was immediately claimed as a big advantage for OWL Full.

> and I have understood one of the design ethics of OWL DL that  
> things be clearer.
>
> Also, the "simple case" pun anything, is out because of the  
> aforementioned exclusions. I don't have confidence that we won't  
> accumulate further exclusions over time.

It's been several months. Shouldn't you put your effort into finding  
the exclusions rather than FUDing?

> So the comparision I see (at the moment) "Everything can be punned  
> to an individua"l versus "Most things can be punned except the  
> different property types and classes / data ranges" (my mistake in  
> earlier message saying datatype).
[snip]

You confuse spec with use. It's much simpler not to *encounter* a  
restriction. More restrictions make encounters more likely.

Cheers,
Bijan.
Received on Tuesday, 1 July 2008 07:02:42 UTC

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