- From: Martin Hepp <martin.hepp@ebusiness-unibw.org>
- Date: Thu, 9 Sep 2010 08:51:34 +0200
- To: Pat Hayes <phayes@ihmc.us>
- Cc: Michael F Uschold <uschold@gmail.com>, semantic-web@w3.org
Hi Michael, Pat: Thanks for your feedback. As said, the main focus of the ontology are areas with short-term business relevance. From my analysis, those are - New and used car listings - Car manufacturers' vehicle specifications - Rental car offers - (Rather generic) rental offers for recreational vehicles, like bikes, boats, etc. I am happy to change the structure of the water vehicles part, but only if there are at least two additional data sources and a total of 10,000 models or offers exposed on the basis of that change, or one deployed (!) application that will depend on the change. Some of you may know that I am a big fan of clean modeling in general and many aspects of OntoClean in general, but ontological correctness is only one of many characteristics of a good ontology, unless impact and practical relevance are not considered relevant. I agree with all of Michael's trade-offs, but again, the VSO ontology does not say that a Kayak is not a boat. It just says that a kayak does not have to be considered a boat by every individual that want to commit to the ontology. It is perfectly fine to make your kayak a vso:Boat, since there are no disjointness axioms between kayaks and boats in the ontology. As a side comment to the community (not to you personally): The reputation of the Semantic Web movement would be a whole lot better if any senior research in the field had tried to actually build at least one non-toy ontology (of any size). With non-toy I mean: 1. Consistent 2. Deployed under a permanent URI 3. HTML documentation 4. Tool support for creating and consuming respective data We do currently have only 8 - 10, maybe 20 serious Web ontologies but > 1,000 papers on the Semantic Web. ;-) Martin On 09.09.2010, at 06:09, Pat Hayes wrote: > > On Sep 8, 2010, at 4:26 PM, Michael F Uschold wrote: > >> There are various tradeoffs: >> • Conceptual simplicity of the ontology, >> • for easy understandabilty >> • for ease of use >> • Alignment with common sense >> • for easy understandabilty >> • to avoid repelling potential users >> • Ontological correctness which should correlate with 2. but may >> be at odds with 1. >> • to align with common sense >> • to increase correctness and scope of usability >> • more correct can often mean more complex >> • Keeping things nice for inference engines >> • to improve functionality in an application >> • Keeping things nice for [semantic] web developers and programmers >> • to encourage use >> IMHO it is dangerous to stray far from common sense - it is too >> expensive in scaring users away by getting surprising and incorrect >> behavior in applications. >> >> IMHO catering too much to the whims of inference engines and making >> life easy for web developers often results in an unfortunate amount >> of messiness in an ontology. >> >> On Mon, Aug 30, 2010 at 11:36 PM, Martin Hepp <martin.hepp@ebusiness-unibw.org >> > wrote: >> Hi Michael, >> Thanks for the feedback! I chose to consider Kayaks as a special >> kind of watercraft in order to exclude them from the domain of all >> properties associated with having a motor, because to my knowledge, >> kayaks are extremely rarely powered by an engine (other than e.g. >> canoes, which occasionally have small electric or combustion >> engines). >> >> This seems to be trading off ontologically correctness and >> alignment with common sense for simplicity and making things nice >> for web programmers and inference engines. I am all in favor of >> simplicity to encourage use, but I think it is dangerous to be too >> out of alignment with common sense - which says a kayak is a boat. >> >> >> By simply also making kayak a subclass of boat, one would recommend >> (*) a lot of properties that 99.9% of the kayaks in the world don't >> have (engine displacement etc.), which will irritate potential >> adopters. >> >> Otherwise, I would have needed rather "ontology expert" classes >> like "motorizableWaterVehicle" etc. This would also require complex >> class definitions for the range / domain definitions, which cause >> practical problems in many pure RDF and RDFS environments (e.g. >> resolving unionOf without an OWL reasoner is a pain for developers). >> >> You seem to be using the term "boat" to mean "motorizable water >> vehicle". I agree that "motorizable water vehicle" is not very >> natural or simple, even if it is ontologically correct. > > Um... don't the (natural) categories of powered boat, sailboat and > rowboat capture the needed distinctions here quite adequately? I > have no idea whether a kayak is usually called a rowing boat, but it > clearly belongs in a natural class of boats propelled by arm muscles > holding a paddle or oar. BTW, there are, or once were, sea-going > ships in all these three categories. > > Pat Hayes > > >> I agree that there can be domain and range issues. I always cringe >> at examples like this where we cater to the whims of the language >> and the reasonsers at the cost of common sense. >> >> You have thought about it longer than I, but intuition and >> experience suggests there is likely a way to keep things reasonably >> simple and also aligned with common sense. >> >> >> >> So it was really just a decision for bringing order to the domains >> and ranges of typical properties. >> >> I hope this modeling compromise is acceptable for all kayakers in >> the world. >> >> Martin >> >> (*) I am well aware of the specific semantics of rdfs:range and >> rdfs:domain ;-) >> (**) I know that you know that I am not saying that a kayak is not >> a boat but just that a kayak does not always need to be a regular >> boat for everybody ;-) >> >> >> On 30.08.2010, at 20:36, Michael F Uschold wrote: >> >> Overall this ontology is just fine, highly suitable for its >> intended purpose. I do have one [hopefully] minor concern. Why is >> a kayak not a kind of a boat? The classification in this ontology >> goes like this: >> • Watercraft >> • Boat >> • Kayak >> • Ship >> The source of this (IHMO) mistake may be in the WIkipedia entry for >> Watercraft: >> >> However, there are a number of craft which many people would >> consider neither a ship nor a boat, such as:canoes, kayaks, rafts, >> barges, catamarans, hydrofoils, windsurfers, surfboards (when used >> as a paddle board), jet skis, underwater robots, seaplanes, and >> torpedoes. >> >> Contradictorily, the opening words in the definition of kayak in >> Wikipedia clearly state that a kayak is a boat: >> A kayak (sometimes generalised as a canoe) is a small human-powered >> boat that traditionally has a covered deck, and one or more >> cockpits, each seating one paddler who strokes a double-bladed >> paddle. >> >> I have been a kayaker for 35 years, and every kayaker I know thinks >> and speaks of their kayak as a kind of boat. In the US, most >> whitewater kayakers consider themselves boaters. >> >> What competency question justifies this classification? >> What is an example of a kayak that is categorically not a boat? >> >> Michael >> >> >> >> On Mon, Aug 30, 2010 at 10:22 AM, Martin Hepp <martin.hepp@ebusiness-unibw.org >> > wrote: >> Dear all: >> >> I am happy to announce the first mature release of the Vehicle >> Sales Ontology [1], a GoodRelations-compliant [2,3] Web vocabulary >> for >> - Cars, >> - Bikes, >> - Boats, >> - etc. >> on the Web of Data. >> >> It can be used by car listing sites, bike or canoe rental services >> and the like. >> >> In combination with >> >> - http://purl.org/goodrelations/v1#owns and >> - http://purl.org/goodrelations/v1#seeks , >> >> it is also possible to expose ownership ("I own a Volkswagen Golf") >> as part of online identity data or purchasing interest ("I am >> looking for a canoe"). >> >> The ontology recommends DBPedia resource URIs as predefined >> qualitative values as much as possible. >> >> Any feedback is very welcome. >> >> Best wishes >> >> Martin >> [1] http://purl.org/vso/ns >> [2] http://purl.org/goodrelations/v1 >> [3] http://www.ebusiness-unibw.org/wiki/ >> Own_GoodRelations_Vocabularies >> >> >> -------------------------------------------------------- >> martin hepp >> e-mail: mhepp@computer.org >> www: http://www.heppnetz.de/ >> skype: mfhepp >> twitter: mfhepp >> >> Check out GoodRelations for E-Commerce on the Web of Linked Data! >> ================================================================= >> * Project Main Page: http://purl.org/goodrelations/ >> * Quickstart Guide for Developers: http://bit.ly/quickstart4gr >> * Vocabulary Reference: http://purl.org/goodrelations/v1 >> * Developer's Wiki: http://www.ebusiness-unibw.org/wiki/GoodRelations >> * Examples: http://bit.ly/cookbook4gr >> * Presentations: http://bit.ly/grtalks >> * Videos: http://bit.ly/grvideos >> >> >> >> >> -- >> Michael Uschold, PhD >> LinkedIn: http://tr.im/limfu >> Skype: UscholdM >> >> >> >> >> -- >> Michael Uschold, PhD >> LinkedIn: http://tr.im/limfu >> Skype: UscholdM > > ------------------------------------------------------------ > IHMC (850)434 8903 or (650)494 > 3973 > 40 South Alcaniz St. (850)202 4416 office > Pensacola (850)202 4440 fax > FL 32502 (850)291 0667 mobile > phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > > >
Received on Thursday, 9 September 2010 06:52:08 UTC