This wiki has undergone a migration to Confluence found Here
Negation Sources
Jump to navigation
Jump to search
Back to Negation Requirements
- Alan Rector, What's in a Code?
- On separation of ontology from terminology & use of "situation" construct to harmonize positive & negative assertions
- Alan Rector, Negation & Null Values (rough notes)
- On preference for "absent" to "negation," at least at first
- SNOMED CT Technical Implementation Guide: see 7.8.2.4.7 Retrieving absent findings
- This section discusses how negation changes the rules for subsumption testing. The solution is to reverse the candidate/predicate relation for Situation with Explicit Context findings using "known absent" or a descendant.
- This approach can probably be generalized; Procedure with explicit context is mentioned. Observable with value "absent" is not.
