Bereiter and Scardamalia describe knowledge building as a way to create new cognitive artifacts. They recognize the importance of the community in building public knowledge artifacts, and of individuals applying innovation to build new artifacts. In the OTTER project, this concept is formalized by layered groups of knowledge topics for OWL-DL documents as listed below:
- DigitalTwin – Unique and private domain building upon Business, Academia, and Universal ontologies.
- Business – Public and private reusable upper level ontologies of business functions. Cataloged by the North American Industry Classification System (NAICS) and built upon Academia and Universal ontologies.
- Academia – Public reusable pattern ontologies from academic disciplines. Catalogued by the Classification of Instructional Programs (CIP) and may be built upon Universal ontologies.
- Universal – Public ontologies for common technical implementation for the execution of process and federation as provided by the Otter Server.
The Otter Server enforces this structure by requiring that an ontology document only import another ontology document from the same layer or from a lower level layer. In other words, a business document can import another business document, an academic discipline document, or a universal document. An academic principle document can only import another academic principle document or a universal document.
The topology applied in the OTTER Project to categorize knowledge is derived from the existing classification codes previously mentioned, and can be presented as a tree of knowledge. The tree has leaves as defined by the North American Industry Classification System {NAICS) for categorizing business types. The limbs are combined academic disciples as defined in the Classification of Instructional Programs (CIP). The tree is dynamically constructed from crosswalks that link NAICS codes to CIP. The roots of the tree are the universal technical ontologies for processing.
A single ontology document is classified with a single code from business, academic discipline, or universal necessity. For business, the document would be found in a leaf. For an academic discipline, a document could be found in multiple limbs of the tree as well as in the trunk of the tree. Universal necessities are the technological roots of the tree.