Sensorica Knowledge

A class can have subclasses that represent concepts that are more specific than the superclass.

Here we discuss general issues to consider and offer one possible process for developing an ontology. We describe an iterative approach to ontology development: we start with a rough first pass at the ontology. We then revise and refine the evolving ontology and fill in the details. Along the way, we discuss the modeling decisions that a designer needs to make, as well as the pros, cons, and implications of different solutions.

In practical terms, developing an ontology includes: �         defining classes in the ontology, �         arranging the classes in a taxonomic (subclass–superclass) hierarchy, �         defining slots and describing allowed values for these slots, �         filling in the values for slots for instances.

We can then create a knowledge base by defining individual instances of these classes filling in specific slot value information and additional slot restrictions.

Slots describe properties of classes and instances:

some fundamental rules in ontology design

There is no one correct way to model a domain— there are always viable alternatives. The best solution almost always depends on the application that you have in mind and the extensions that you anticipate. 2)      Ontology development is necessarily an iterative process. 3)      Concepts in the ontology should be close to objects (physical or logical) and relationships in your domain of interest. These are most likely to be nouns (objects) or verbs (relationships) in sentences that describe your domain.

how detailed or general the ontology is going to be

what we are going to use the ontology for

concepts in the ontology must reflect this reality

We suggest starting the development of an ontology by defining its domain and scope. That is, answer several basic questions: �         What is the domain that the ontology will cover? �         For what  we are going to use the ontology? �         For what types of questions the information in the ontology should provide answers? �         Who will use and maintain the ontology?

plan to use

domain

If the people who will maintain the ontology describe the domain in a language that is different from the language of the ontology users, we may need to provide the mapping between the languages.

One of the ways to determine the scope of the ontology is to sketch a list of questions that a knowledge base based on the ontology should be able to answer, competency questions

These competency questions are just a sketch and do not need to be exhaustive.