A "lexically-suggested logical closure" metric for medical terminology maturity

Medical Terminologies are becoming increasingly expressive secondary to their increase in size, and are becoming increasingly difficult to analyze secondary to inconsistencies in their use and complex interrelationships that are often not explicitly defined. To address these problems, SNOMED-RT is being developed to allow consistent use, and to define explicitly interrelationships between terms. Ensuring the quality of a terminology system like SNOMED-RT presents new challenges which we are trying to address with theoretically-grounded methodologies for quality management. Here we describe an initial metric toward achieving this goal called "lexically-suggested logical closure." We explain how this metric can be useful for tracking the maturity and quality of a terminology, and apply this metric to track the progress of SNOMED-RT development over a portion of its life-cycle.