caBIG® Semantic Infrastructure - Overview - Initiatives

Assessment of semantic unification of compositional and derivational models

This initiative is contingent on adoption by caBIG/CBIIT of a more than one architectural style. It focuses on assessing the ability of the resources developed in Initiative 1, Initiative 3 and Initiative 5 to be aggregated in such a way as to provide semantic unification of artifacts from different architectural styles.

The semantic infrastructure must support clinical domains governed by regulation and complex business relationships, and also research where agility is paramount. Experience has shown that caBIG's model-driven, backend loaded labor intensive semantics does not comfortably support the research domain, hence the attempt to develop semantics from line of business artifacts (See Initiative 2). The RM-ODP requires well described information models that can be tied However support of both clinical and research domains probably will require changes to caBIG/CBIIT architectural model external to the semantics infrastructure. The top-down "derivative" architectural model that works reasonable well for the clinical space is a poor fit for the research domain. caBIG/CBIIT architects have begun to discuss use of bottom-up "compositional" architecture as an alternative that may be better suited to the needs of the research domain. See Table 2 for a summary of the properties of derivative and compositional architecture approaches.

Table 2: High level characteristics of derivative and compositional architecture
(courtesy of A Honey & J Landgrebe)

Assessment and adoption of the compositional architecture approach as a solution to research domain needs is not part of this concept of operations. If, however, two architectural approaches were adopted by caBIG/CBIIT, the semantic infrastructure would have to support both.

The ii4sm architects have envisioned the logical components of the semantic infrastructure shown in Figure 2, 4 and 5 organized into a "semantic backbone" composing the three sets of interdependent semantic services as shown in Figure 8. ii4sm believes that a semantic backbone comprising both types of shared elements (from derivational and compositional approach) can be used to resolve the semantics of shared information from both sources. Figure 8 is a very high level representation that includes several components that are not fully architected, however it seems clear that in addition to the work done in Initiative 1, Initiative 3 and Initiative 5 (which would realize the resources called Information Management, Rules Management and Terminology Management respectively) additional integration would be needed to enable the components to operate as implied in Figure 8.

Figure 8: Grouping of Semantics Services. Some resources not explicitly represented (e.g. ISO 11179
Repository and ISO 21090 Service). Courtesy of A Honey & J Landgrebe

This Initiative will encompass definition and realization and testing of the interactions among the model, terminology and rules components. These tests would be designed to assess the backbone's ability to correctly represent semantics of services designed top down (derivative) and bottom up (compositional) – assuming both styles would be required to support the clinical and research domain's operations. (Assessment of the ability of the compositional approach to support the need of the research domain for rapid evolution is not part of this proposal. That is assumed to be an initiative undertaken by the life sciences).

Requirements

;Initiative 7 section of the Requirements/Initiatives Master List

Use Cases

Forum

;Initiative 7 - Assessment of semantic unification of compositional and derivational models