[Top] [All Lists]

Re: [ontolog-forum] Current Semantic Web Layer pizza (was ckae)

To: "[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Randall R Schulz <rschulz@xxxxxxxxx>
Date: Sun, 16 Sep 2007 17:11:57 -0700
Message-id: <200709161711.57200.rschulz@xxxxxxxxx>
On Sunday 16 September 2007 16:32, Mills Davis wrote:
> Randall,
> ...
> 3.  But, another issue that is nagging me is concerns the advantages
> of logical symmetry and sequence neutrality. Why is a processing
> distinction made between forward and backward axioms? Wouldn't the
> impact of all possible informational variables be (pre)computable at
> the time the backward/forward axiom was formulated? I guess what I'm
> probing is the notion of symmetry of expression.  If we view
> knowledge as a constraint space of conditional and unconditional
> expressions (rational paths) containing both dependent and
> independent variables, then isn't it possible to reason over the same
> mesh by changing what we consider independent and dependent, and thus
> address different types of questions? For example, I see this idea
> coming up recently in the discussion of "continuous search" and
> "perpetual analytics.."    (01)

The burden of deciding whether pre-computed consequences are 
advantageous is placed upon the knowledge engineer. Surely it would be 
better to have the system make that determination, but at this point 
(*), that is not a practical, feasible or possible computation.    (02)

In essence, this is a pragmatic distinction that Cyc foists upon the 
knowledge engineer.    (03)

However, a key fact to keep in mind is that the "forward" vs. "backward" 
distinction does not influence the inferential capabilities of Cyc nor 
the logic it implements (**). It is purely a performance issue. (In 
fact, a classic space vs. time tradeoff.)    (04)

(*) I have not used Cyc since about 2001. I cannot actually represent 
this as the current state of affairs in the Cyc knowledge 
representation and inference system in 2007.    (05)

(**) Whatever that may be...    (06)

As a software engineer, this is a reasonable approach to practical 
system optimization. As a knowledge engineer, it's an unwanted 
intrusion of the implementation realm into the knowledge representation 
realm.    (07)

> Mills    (08)

Randall Schulz    (09)

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (010)

<Prev in Thread] Current Thread [Next in Thread>