284 12 Building Bioinformatics Ontologies
cover medically relevant events for patients and must also allow for personnel to
make notes about patients and events. Events include tests, drug prescriptions, and
operations performed. All events must be categorized using standard categories.
The purpose of this ontology is summarized in the following table:Why Assist medical practice
What Relevant medical events
Who Medical personnel
When Ten years
How Diagnosis and trend analysisRequirements for software development are often expressed usinguse case
diagrams. Use case diagrams are part of the Unified Modeling Language
(UML) (UML 2004). Although use case diagrams are intended for devel-
oping software, the technique can also be used for ontology development.
Use case diagrams are primarily useful for specifying who will be using the
ontology and how it will be used. They are not an effective way to spec-
ify why the ontology is being developed, what will be covered, and how
long the ontology will be used. A use case diagram shows the relationships
amongactorsanduse cases. Actors represent anything that interacts with the
system. An actor is usually a role played by a person, but it can also repre-
sent an organization or another computer system. A use case represents an
interaction with the system. An ontology is not a computer system, but one
can identify the actors that interact with it, as well as the components with
which the actors interact. The requirements for the medical chart ontology
could be represented diagrammatically as in figure 12.1. This diagram was
created using the ArgoUML tool (Tigris 2004).Summary
- Before developing an ontology, one should understand its purpose.
- The purpose of the ontology should answer the following questions:
- Why is it being developed?
- What will be covered?
- Who will use it?
- How long will it be used?
- How will it be used?