Dan, We are talking apples and oranges. I am talking about the semantics of "class", of which the Observation class is an example. [1], for example, says, "A class is the descriptor for a set of objects with similar structure, behavior, and relationships." (p. 50) You are talking about aggregations, like an instance of Population is an aggregation of Person instances. The Population class still denotes a set of instances, each of which is an aggregation of Person instances (e.g., the population of subjects enrolled in trial X). The idea of a class as denoting a set of individuals is common to UML, frame representation, and OWL. I would like to view, in any of these formalisms, the Observation class as denoting a set of individual observations, and the WhiteBloodCellCountObservation class as denoting a subset of the observations whose code is the LOINC code for white blood cell count. Samson [1] Rumbaugh, Jacobson, & Booch, The Unified Modeling Language Reference Manual, 2nd edition. -- Samson Tu email: swt@stanford.edu Senior Research Scientist web: www.stanford.edu/~swt/ Center for Biomedical Informatics Research phone: 1-650-725-3391 Stanford University fax: 1-650-725-7944 On Jul 23, 2008, at 8:02 PM, Dan Russler wrote: > Hi Samson, > > Sorry for my older-style jargon... > > Here is the Wikipedia entry on collection/aggregation. We often > called these classes "collectors" in jargon: > >
Received on Thursday, 24 July 2008 04:20:32 UTC