People model for different reasons and there can be different types of models.
While I am quite convinced that Bold Eagle as a specie is different from a set of all occurrences of the individual bold eagles and, thus, each deserves their own URI, I can't prevent you from designing your models the way you chose. If you feel that there are cases where your needs are best met by punning, it is a design choice that I assume you would make. The original question was about SHACL and whether it would have some inherent issues with this approach. The answer was no. If I am asked, my recommendation would be to avoid punning. This recommendation is not specific to TQ tooling, it is a general modeling recommendation. Having had now nearly 20 years to think about and work on such modeling issues independently and with colleagues whose judgement I respect, I believe punning mixes concerns and causes more problems than it solves. However, as I said, everyone is free to make their choices. Besides, there can always be exceptions to any rule. > On Sep 8, 2018, at 11:48 PM, Rob Atkinson <robatkinson...@gmail.com> wrote: > > > Without contradicting anything Irene says (which is obviously the gold truth > for the TQ environment) I'd also like to offer an additional architectural > perspective (cos thats my day job) that may also be useful, and i'm always > seeking to identify best practices here... > > A few separate concerns here: > > 1. We need to be careful with statements like "mean different things" - I > think this is a classic case of the httpRange14 issue - i.e. distinguishing > between identifiers of "things" vs identifiers of "representations of things" > Representations have shapes, i.e. sets of properties - and this is a design > choice about how to model a thing > 2. Under the Open World Assumption, anyone can say anything about any topic > using whatever representation they choose - so this means its another design > decision (at a high level of your architecture) how to manage closure of > graphs in a distributed environment. (TQ is largely concerned with your > local node - and supports a particular set of closure patterns, but this is > all about collapsing the open world into a tractable sub graph _that you > choose_ > 3. The example given is actually a strong example of why (IMHO) some systems > may need to support OWL punning ... > > The model for the concept of "Endangered Species" is inconsistent with poor > old "Harry" - which usefully tells us the model is broken or not applied > properly to Harry ... > > in fact there is no such thing as an Endangered Species as a class of all > individuals. "Endangered" is a status applied explicitly to a species within > a certain spatio-temporal context (usually a date of a politically negotiated > determination within a given jurisdiction), Scientifically derived concepts > of endangered may also co-exist - and different evidence and modelling may > suggest that a designation is more or less appropriate - a species may be > endangered by any rational scientific assessment, bit not declared so, or > declared so and actually extinct. There is usually a "extinct in the wild" > explicit status too - so the set of eagles is actually the "set of eagles in > the wild" - which poor Harry isnt. There is nothing wrong with the model of > Bald Eagle - it can be instance of species and a class of a set of > individuals. Its just not a subclass of Endangered Species according to the > model implied in the example. Endagered Species is a different thing with a > relationship to a Species, and individuals may or may not be instances of > both. > > Of course, you may manage your context to only include a given jurisdiction > (or scientific viewpoints) view - in which case the model is correct but the > assignment of Harry to a specimen assumed to be "in the wild" is incorrect. > So you probably need to handle instances and classes in many cases - > > (Having done some modelling of biodiversity and Web scale citizen science > interoperability concerns, this is easy for me to spot - and IMHO > demonstrates the potential power of the semantic approach) > > > > > On Saturday, 8 September 2018 22:32:12 UTC+3, Irene Polikoff wrote: > Punning is the use of the same word to mean different things. > > In modeling, it is traditionally used to refer to the approach where the same > resource is used both as an instance of some class (other than the pre-built > RDFS/OWL/SHACL classes) as well as declared to be a subclass of some class. I > am excluding the pre-built classes from this because that takes us into a > topic of meta modeling which can be seen as related, but is somewhat > different. > > My e-mail was about this topic and the differences between a concept and a > set of occurrences of this concept in the world. > > When a modeler defines a class they make statements that must be true for all > class members and they define characteristics (properties) of such members. A > classic example of this (classic because you come across it described in > Wikipedia and in discussions amongst the modeling community) is Bold Eagle as > a specie vs Harry, a Bold Eagle. Bold Eagle is an endangered specie. Harry, > however, is not endangered - that is unless someone is currently trying to > kill it. Harry has his own properties and we need a class to describe these > properties. Indeed, this does take us into a topic of taxonomies vs > ontologies. > > If you are seeking a recommendation from TQ on how to model in these > situations, please see the attached Ontologies vs Taxonomies slides. Our > recommendation is to be clear on the distinctions and to maintain these > resources separately. The presentation offers practical advice on how to > organize your models and data using TopBraid EDG. > > > -- > You received this message because you are subscribed to the Google Groups > "TopBraid Suite Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to topbraid-users+unsubscr...@googlegroups.com > <mailto:topbraid-users+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "TopBraid Suite Users" group. 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