Definition of Reference Archetype

We currently have the following definitions:

Reference Model

A Reference Model is an information model which defines a set of modelling patterns upon which the clinical models are defined. All CIMI clinical models will be defined by constraining the CIMI reference model. The CIMI reference model is intended to be instantiated with patient data, which conforms to the constraints defined by the associated clinical model.

CIMI Reference Model

The information model on which CIMI's clinical models (i.e. archetypes) are defined.

Usage Notes: This reference model defines a rigorous and stable set of modelling patterns, including a set of complex data types and structural patterns (e.g. composition, entry). All CIMI clinical models will be defined by constraining the CIMI reference model.

When we started it, it was easy to differentiate the CIMI Reference Model from the CIMI clinical models. The CIMI Reference Model was modeled using UML . The CIMI clinical models were modeled in AOM as constraints on the CIMI Reference Model.

Since these definitions were recorded, we arrived at an interesting notion, where the CIMI Reference Model is now composed of two parts: a UML based "mini CIMI" Reference Model and an AOM based collection of Reference Archetypes.

A Reference Archetype is identified by the line:

other_details = <["model_level"] = <"reference">

in the ADL representation or its equivalent in other formats. The presence of this line affects how the archetypes are represented in the ADL Workbench, but it doesn't actually affect the semantics. At the moment there is no semantic or behavioral difference between a "Reference Archetype" and any other generic archetype, meaning that, at the moment, the best definition we can provide is:

"A Reference Archetype is an Archetype with "model_level = reference" asserted in the other_details section."

The above definition is obviously inadequate. What we need to do is to describe a set of rules that apply to Reference Archetypes, which will provide us with a more useful definition. The resulting rules can either be enforced within the tooling or informally by the modelers themselves.

Rules:

  1. A (CIMI) Clinical Model constrains a (CIMI) Reference Model. A Clinical Model may not include Reference Archetypes.
  2. A Reference Modeldefines a set of modeling patterns upon which the clinical models are defined.A Reference Model consists of a UML Reference Model and a set of zero or more Reference Archetypes. A Reference Information Model does not include any "normal" (i.e. non-Reference) Archetypes.
  3. A UML Reference Model defines a set of modeling patterns using the basic constructs available in UML or BMM.
  4. A Reference Archetypeis an Archetype that:
  5. is identified with "model_level = reference" and
  6. can use elements in the UML Reference Model and other Reference Archetypes in its definition. A Reference Archetypemay not specialize or reference a "normal" (non-Reference) Archetype.
  7. If a Reference Information Model includes at least one Reference Archetype, all archetypes defined in the Clinical Modelthat constrain it must specialize another archetype.

This leaves us with two patterns:

The first pattern is when a reference model consists solely of a UML Reference Model and does not contain any reference archetypes. (Normal) Archetypes can constrain and reference classes in the UML Reference model and/or other archetypes

The second pattern occurs when there is one or more Reference Archetype. Reference Archetypes may reference or constrain classes in the UML Reference Model as well as other Reference Archetypes. There may be no non-reference archetypes in the Reference Model. Normal (non-reference) archetypes that comprise the clinical model may specialize or reference any other archetype, but may not (directly) constrain classes in the reference model.