- From: Ken Laskey <klaskey@mitre.org>
- Date: Tue, 24 Jul 2007 09:59:37 -0400
- To: Peter.Vojtas@mff.cuni.cz
- Cc: "Kathryn Blackmond Laskey" <klaskey@gmu.edu>, public-xg-urw3@w3.org, "Umberto Straccia" <umberto.straccia@isti.cnr.it>
Peter, We would always like to have "exact" information, but any measurement has a degree of inexactness/uncertainty based purely on the preciseness of the measuring instrument. At a crime scene, a suspect may be described as tall but the accuracy depends on what the observer considers tall, the vantage point from which the observer saw the suspect, and whether the suspect was wearing shoes with heels. Also, was the suspect tall in the context of a society where the average height is 162 cm or 175 cm? Making use of the fact that the suspect was "tall" requires many assumptions, most of which are implied in conversation but never explicitly stated. What does this tell us about what needs to be represented in terms of uncertainty? Ken On Jul 24, 2007, at 9:29 AM, Peter Vojtáš wrote: > > I personaly would prefer to know the exact height of John and decide > on my background and intention whether he is or not tall. > So I am afraid that I do not understand where such an information > can appear > Peter > > > Please note my changed address Peter.Vojtas@mff.cuni.cz > > > > ----- Original Message ----- > From: Kathryn Blackmond Laskey [mailto:klaskey@gmu.edu] > To: Umberto Straccia [mailto:umberto.straccia@isti.cnr.it], > public-xg-urw3@w3.org > Subject: Re: [URW3 public] OWL extensions [was Re: [URW3] ... three > questions based on the last telecon] > > >> >> >>>> .... you can extend the language and the inference mechanism or >>>> express and process the uncertainty within the standard language. >>>> >>>> tall(John) : 0.7 >>>> >>>> vs >>>> >>>> tall(John, 0.7) >>>> >>>> (... in both cases, without saying what 0.7 represents) >> >> Independent of which way we go on tall(John) : 0.7 or tall(John,0.7), >> it will not be enough just to annotate sentences with a number >> expressing some degree of certainty or plausibility or membership or >> whatever. To do probabilistic reasoning, we need to be able to make >> conditional independence statements, and to express conditional >> probabilities. To do probability tractably depends on representations >> composed out of local modules, and these local modules are >> parameterized by conditional probabilities, not absolute >> probabilities. >> >> K >> >> > > ------------------------------------------------------------------------ ----- Ken Laskey MITRE Corporation, M/S H305 phone: 703-983-7934 7151 Colshire Drive fax: 703-983-1379 McLean VA 22102-7508
Received on Tuesday, 24 July 2007 13:59:59 UTC