At 00:20 08/03/2005, Thomas Beale then Kerry wrote: >>A pragmatic approach would be to do what you say. We could probably >>argue for this just on the basis of the fact that many reference models >>(i.e. object models) are not well constructed, and out of the control of >>the archetype designers, and/or that models consdered good today are >>shown up later on by changing requirements, which changes the validity of >>inheritances such as the one Kerry points out. > >Yes, that's the angle I'm coming from (where we don't control the >reference model). > >And in any case, I don't see the openEHR following the purist road of >having FullySpecifiedDateTime or >ObjectIdThatIsntArchetypeIdNorTerminologyIdEtc :-)
Absolutely! Further, regarding the choice between a specific attribute that could be constrained and the disjoint inheritance modification suggested by Tom, I think the former would, in any case, be cleaner (I imagine we'd put it in the C_OBJECT class). There would be just this one place in the model to change rather than changing the inheritance everywhere where the more normal inheritance is used, and would have general applicability. The latter would probably also lead to a certain unwanted dissimilarity between the Archetype model and the Reference model in a few places. Please also note (as Sam has just pointed out) that, in the latest Archetype Model, there is a full set of attributes in the C_ classes for dates and times that already allows very specific constraints to be placed on the parts. Regards David >Kerry > > >- >If you have any questions about using this list, >please send a message to d.lloyd at openehr.org * David S.L. Lloyd, Technical Consultant * CHIME - Centre for Health Informatics and Multiprofessional Education, at UCL * E-Mail: d.lloyd at chime.ucl.ac.uk Tel: +44 (0)20 7288 3364 * Web: www.chime.ucl.ac.uk/~rmhidsl#contact - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
