Folks, I'm a little concerned about the complexity of the temporal reasoning of the CRM; it's getting increasingly powerful, offering all kinds of temporal operators and sophisticated reasoning for disciplines that need it (such as archaeology), but at the same time it's becoming increasingly cumbersome for simple tasks, such as recording an individual's birth and death dates.
As an example, here are some example mappings from the RLG Cultural Materials data model (which I'm currently working on for the meeting): 1. Actor Start Date: Actor's birth year, if known. E39 Actor <P92 brought into existence (was brought into existence by)> E63 Beginning of Existence <P4 has time-span (is time-span of)> E52 Time-Span <P82 at most within> E61 Time Primitive 2. Actor End Date: Actor's death year, if known. E39 Actor <P93 took out of existence (was taken out of existence by)> E64 End of Existence <P4 has time-span (is time-span of)> E52 Time-Span <P82 at most within> E61 Time Primitive 3. Actor Date String: Text version of the actor's lifespan (birth and death) dates for display, as provided by the contributor. There is no mapping of this element's sematics to the CRM that I can see, since there is no shortcut from actor to timespan without going through beginning of existence and end of existence, and this element combines the two concepts. I'm not arguing that the model shouldn't support the sophisticated temporal reasoning, but it seems a little perverse to have to use it for something as simple as a person's birth and death dates... Couldn't we have a direct short cut such as E21 Person <P4 has time-span (is time-span of)> E52 Time-Span? Cheers, T. ---------------------------------------------------------------------- Tony Gill <> [email protected] Research Libraries Group <> http://www.rlg.org/ 1200 Villa Street, Mountain View, CA 94041 USA Voice: +1 (650) 691-2304 <> Fax: +1 (650) 964-1461 martin <[email protected]> Sent by: [email protected] 30/01/2002 02:11 AM To: [email protected] cc: Subject: Re: [crm-adhoc] Re: [crm-sig] Issue 4, scope notes Oops, You are probably right. Who volunteers to give it the appropriate cultural touch? Martin Tony Gill wrote: > > Martin, > > I think maybe you are missing mathematics and physics at the moment -- > this scope note will TERRIFY museum documentation people! > > Cheers, > > T. > ---------------------------------------------------------------------- > Tony Gill <> [email protected] > Research Libraries Group <> http://www.rlg.org/ > 1200 Villa Street, Mountain View, CA 94041 USA > Voice: +1 (650) 691-2304 <> Fax: +1 (650) 964-1461 > > martin <[email protected]> > Sent by: [email protected] > 29/01/2002 11:45 AM > > > To: [email protected] > cc: > Subject: [crm-sig] Issue 4, scope notes > > Dear All, > > In Paris we decided to add to the E2 Temporal Entity the well-known > temporal relationships from > J.F.Allen, 1983, which can be fairly regarded as a standard in Knowledge > Representation. > I terms of directed, bidirectional properties as we use in the CIDOC CRM, > they can be defined as: > > before (after) : E2 Temporal Entity > meets in time (met-by in time): E2 Temporal Entity > overlaps in time (overlapped-by in time): E2 Temporal Entity > during (includes in time): E2 Temporal > Entity > starts (started-by): E2 Temporal Entity > finishes (finished-by): E2 Temporal Entity > equal in time: E2 Temporal Entity > > where the postfix "in-time" is used to disambiguate from spatial or > spatiotemporal relationships, that appear > lower in the IsA hierarchy of entities in the CIDOC CRM. > > Here my proposal for a scope note: > > The temporal relationships relate a Temporal Entity X, the domain, with a > Temporal Entity Y, the range. > Let us denote the real outer temporal bounds for the Entity X and Y by the > dates X-,X+ and Y-,Y+, where > "-" describes the lower and "+" the upper bound. These are the real > narrowest limits, in which the > Temporal Entity occurred, independent from our knowledge about them. The > relationships in parenthesis, > like (after), are the inverse ones, i.e. those which we obtain by > interchanging X and Y in the definition. > > before (after) : X ended at a date before the one when Y started : X+ < Y- > > meets in time (met-by in time) : X ended at the date when Y started : X+ = > Y- > > overlaps in time (overlapped-by in time): X started before Y started, but > ended within the duration of Y: X-<Y-, Y-<X+, X+<Y+ > > during (includes in time): X started and ended within the duration of Y: > Y-<X-, X+<Y+ > > starts (started-by): X started with Y but ended before it: X-=Y-, > X+<Y+ > > finishes (finished-by): X started after Y but ended simultaneously: > X-<Y-, X+=Y+ > > equal in time: X started with Y and ended with Y: X-=Y-, X+=Y+ > > ======================================================== > > My intuition about cultural documentation practice leaves me when to > decide about the application of these relationships > to spatiotemporal cases, or other dimensions of possible specializations > of Temporal Entities. > As we have decided not to attach these properties to the associated time > spans, there are two possible interpretations: > > Given two "bubbles" in Space-Time, like Bronze-Age and Iron-Age, a term like "overlaps in > time" > may mean: > > 1) At any given point in space, at any given settlement, Bronze-Age > overlaps more or less Iron-Age. > 2) We don't know if at any given point in space, Bronze Age overlaps with > Iron-Age, but at least when Iron-Age > first started in settlement A, Bronze-Age still prevailed in > settlement B, and when Bronze Age started, Iron-Age has > not started anywhere, and before Iron-Age ended in the last settlement, > Bronze-Age ended in its last settlement. > > Both interpretations are equally valid, but I think one of those must be > culturally more relevant, i.e. > closer to the phenomena we regard worthwhile documenting. > > If interpretation 1) is the relevant one, the relationship "falls within" > of E52 Time-Span is NOT synonymous > with the relationship "during" of the associated Time-Spans, which makes > some sense. Another aspect is, > that trivial relationships between known dates need not be expressed by > explicit temporal relationships. > Those are only needed for phenomena with nknown absolute dates. > > If interpretation 1) is the relevant one, > "overlaps","starts","during","finishes" imply spatiotemporal overlap - > in contrast to interpretation 2). This may be wanted. This may make the > "pure spatiotemporal overlap" > advocated for in one of my previous messages unnecessary. > > If interpretation 1) is the relevant one, "equal" becomes spatiotemporally > equal. This may be improbable for > any real case, except the cultural periods of Atlantis starting end ending > with its emerging and drowning in the sea... > > A slight modification of interpretation 1) may be even more realistic: > At any given point in space, at any given settlement, where both, > Bronze-Age and Iron-Age occurred, Bronze-Age > overlaps.... > > This leaves space for spaces, where the one or the other period did not > occurr. This renders a "temporally equal" > different from a "spatiotemporally equal" (or "coocurrent"). > Alternatively, "temporally equal" may be defined only > on the associated Time-Spans. > > As these operators were required by archeologists, we need a competent > comment on this issue. > > Martin > -- > > -------------------------------------------------------------- > Dr. Martin Doerr | Vox:+30(810)391625 | > Principle Researcher | Fax:+30(810)391609 | > Project Leader SIS | Email: [email protected] | > | > Information Systems Laboratory | > Institute of Computer Science | > Foundation for Research and Technology - Hellas (FORTH) | > | > Vassilika Vouton,P.O.Box1385,GR71110 Heraklion,Crete,Greece | > | > Web-site: http://www.ics.forth.gr/proj/isst | > -------------------------------------------------------------- > -- -------------------------------------------------------------- Dr. Martin Doerr | Vox:+30(810)391625 | Principle Researcher | Fax:+30(810)391609 | Project Leader SIS | Email: [email protected] | | Information Systems Laboratory | Institute of Computer Science | Foundation for Research and Technology - Hellas (FORTH) | | Vassilika Vouton,P.O.Box1385,GR71110 Heraklion,Crete,Greece | | Web-site: http://www.ics.forth.gr/proj/isst | --------------------------------------------------------------
