- From: Pat Hayes <phayes@ihmc.us>
- Date: Wed, 8 Sep 2010 23:09:11 -0500
- To: Michael F Uschold <uschold@gmail.com>
- Cc: Martin Hepp <martin.hepp@ebusiness-unibw.org>, semantic-web@w3.org
- Message-Id: <0943B14A-378C-4E57-8C90-46EC401C2ADA@ihmc.us>
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
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Received on Thursday, 9 September 2010 04:09:49 UTC