- From: Guus Schreiber <schreiber@swi.psy.uva.nl>
- Date: Thu, 28 Mar 2002 15:21:07 +0100
- To: Jim Hendler <hendler@cs.umd.edu>
- CC: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>, www-webont-wg@w3.org
Jim Hendler wrote: > >- default values for attributes > > Not even in Full OWL > > I think the term "default" is used differently here - in UML the > defaults can be, essentially, monotonic, in the sense that it is a > default that a female mammal lactates to feed its young (this is > definitional, no exceptions in the natural world) -- using the > notion of default as "All of them have this value so it doesn't have > to be specified on each" I don't think that this is the UML semantics for default value. Well, actually most UML books do not do a good job at defining it. The User Guide of the three amigo's [1] gives the example of a class "Wall" with an attribute "isLoadBearing" which has a default value "false" (clearly not true for every wall). No further explanation is given of what may constitute a default value. The OMG UML document [2] uses the term "initial" instead of "default" (which seems to stem from a programming view). Guus [1] Booch, Rumbaugh & Jaconson. The Unified Modelling Language User Guide. Addison Wesley, 1999. [2] http://www.rational.com/media/uml/post.pdf -- A. Th. Schreiber, SWI, University of Amsterdam, Roetersstraat 15 NL-1018 WB Amsterdam, The Netherlands, Tel: +31 20 525 6793 Fax: +31 20 525 6896; E-mail: schreiber@swi.psy.uva.nl WWW: http://www.swi.psy.uva.nl/usr/Schreiber/home.html
Received on Thursday, 28 March 2002 09:24:30 UTC