- From: Dan Russler <dan.russler@oracle.com>
- Date: Tue, 22 Jul 2008 20:24:34 -0400
- To: Samson Tu <swt@stanford.edu>
- CC: "Kashyap, Vipul" <VKASHYAP1@PARTNERS.ORG>, "Elkin, Peter L., M.D." <Elkin.Peter@mayo.edu>, public-semweb-lifesci@w3.org, public-hcls-coi@w3.org
- Message-ID: <48867A42.9070308@oracle.com>
Hi Samson, I agree...It is wrong to confuse the process of creating an instance in the narrow sense (where the structural attributes and other attributes are constrained to specific values) and creating an incremental constraint on the structural attributes and code that allow one to define "more concrete information models." By constraining classCode, moodCode, and code to smaller value sets, one is creating more concrete models, not creating instances in the narrow sense. In creating an instance, one is constraining classCode to one value, moodCode to one value, and constraining the CD datatype for code to a single semantic meaning as well as setting values for other attributes (that might be updated later). Dan Samson Tu wrote: > My understanding of the HL7 RIM is that, when you clone a RIM class, > such as Observation, into a specific domain model class (e.g., > WBC_Count_Observation), you are placing restrictions on the RIM class, > i.e., constraining the cloned class's properties to have specific > values or to take values from a restricted vocabulary domain. The > process, I think, is characterized as creating a subclass of the RIM > class, not an instance. If you understand metaclass/class/instance in > the sense of OKBC, WhiteBloodCount as an instance of Observation where > code is specified to be the LOINC code for WBC means that code is not > a property of Bob's WBC. To query for the code, you need to go up the > class level. > > I see no advantage in modeling the domain classes (detailed clinical > models) as instances of HL7 RIM classes. What's wrong with seeing them > as specializations? > > Samson > > Kashyap, Vipul wrote: > >> Dan, >> >> Looks like there is increasing convergence in our view points and >> some minor divergences. >> >> <dan> I'm confused...can you illustrate in UML, perhaps with the >> blood pressure example? /> >> [VK] The UML Diagram illustrating WBC is attached with this >> e-mail (GIF format). Look forward to your thoughts on this issue. >> >> <dan> depends what one means when one says they "create" an >> ontology. An ontology is just another name for a belief system. >> When one writes down one's beliefs, one is not really creating an >> ontology. /> >> [VK] Well, that could be part of the confusion. Another viewpoint >> is that an ontology is a knowledge artifact that has a broad >> consensus on what it means. >> >> <dan> looks like the antecedent to my statement "In small >> domains..." is lost somewhere above. In any case, in small >> domains, one can easily get a picture of all the classes on a >> small diagram that is easy for people to look at together. In >> large domains, the multitude of classes makes the diagram huge >> and makes it difficult to express the essentials on one computer >> screen or piece of paper (too many trees to see the forest). The >> HL7 UML model of the RIM that makes mood and class code >> attributes is simply a pictorial approach that assists discussion >> in many venues, i.e. one doesn't need a huge piece of paper on >> the wall! Again, not to get hung up in pictures of concepts. >> Focus on the concepts. /> >> [VK] Yes, the requirement to make a model compact shouldn't >> negatively impact the understandability of the model. Mood and >> type codes can be very tricky to understand. Also these are >> some sort of attributes at layer 1 as opposed to Layer 2. In some >> cases, the model may be more understandable in one explicitly >> represents subclasses based on these codes. >> >>>> [VK] OK, then what you are suggesting is that a >>>> template is logically equivalent to a set of >>>> constraints on the information model. Would be >>>> interested in representing these conformance statements >>>> as a set of OWL axioms >>>> >> <dan> I agree...Adding an OWL version of these conformance >> statements would be a great next step. /> >> >> I hope this long-winded description helps in this "multi-layered >> Knowledge Representation" discussion. How one classifies the >> concept of "context" for a given concept, or the concept of >> "conformance testing the constraints on an aggregation of >> structure and vocabulary" in a multi-layer Knowledge >> Representation is not clear to me. >> >>> <dan> There are many kinds of "conformance." One basic >>> example is testing the contents of a data entry field before >>> committing the contents to the database to make sure the >>> contents have the right kinds of characters, e.g. numeric, >>> alphabetic, etc. >>> [VK] This is basically syntax checking which checks for the >>> format in which data is represented and is not an >>> information modeling or semantics issue. >>> >>> Schematron testing in CDA tests the conformance of the XML >>> structure and the codes and other values within the XML >>> structure (think terminology) to make sure the wrong codes >>> aren't used in a specific XML structure. >>> [VK] XMl structure testing can be tricky because the >>> healthcare IT community has used XML Schema to represent >>> information models. XML Schema is a language designed to >>> describe the format and structure of XML documents in >>> contrast with languages >>> such as RDF, OWL and UML which seek to describe the >>> semantics underlying these documents. So "checking for >>> conformance of XML Structure" could either (A) check for the >>> validitiy of the structure of the XML Document or for (B) >>> validity of the information >>> model (R-MIM) underlying the XML document. What would be >>> relevant is (B) and we could try to use OWL axioms to >>> describe the type of conformance statements represented by (B) >>> Finally matching terminologies is a semantics issues and >>> OWL/Description Logics have been used to represent Snomed >>> and terminology matchin can be expressed in terms of OWL >>> subsumptions. >>> >> <dan> Again...agreed...OWL is a natural tool for this task /> >> >>> >>> I'm sure that a broader definition of conformance can be >>> created that includes things as basic as character >>> validation and as complex as information model/vocabulary >>> model validation. /> >>> [VK] What can easily be implemted using OWL is information >>> model/vocabulary validation >>> >>> In Summary, we could propose the following Task Force which >>> looks at the following aspects as a part of HCLSIG: >>> (A) Determine the feasibility of OWL as a common >>> representational formalism for healthcare delivery >>> information models and terminologies >>> (B) Define and implement the notion of "Semantic >>> Conformance" of an information model to HL7/RIM + >>> Terminologies (may require a restructuring of the RIM to >>> some extent) >>> >>> Let me know what your thoughts are on this and we can figure >>> out the next steps. >>> >>> Cheers, >>> >>> ---Vipul >>> >>The information transmitted in this electronic communication is intended only >>for the person or entity to whom it is addressed and may contain confidential >>and/or privileged material. Any review, retransmission, dissemination or other >>use of or taking of any action in reliance upon this information by persons or >>entities other than the intended recipient is prohibited. If you received this >>information in error, please contact the Compliance HelpLine at 800-856-1983 and >>properly dispose of this information. >> >> >> >> >> >> ------------------------------------------------------------------------ >> > >-- >--------- >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 > > > > >
Received on Wednesday, 23 July 2008 00:26:25 UTC