Creating ontological definitions for use in science

Ontological definitions provide clarity and facilitate communication which accelerate the development of understanding and the accumulation of evidence about the world. It is hard to write good definitions. Too often they are partial, vague, or fail adequately to characterise the entity to which they refer. Ontological definitions are descriptions of entity classes or relationships that represent their essential properties in such a way that the defined entities are uniquely and fully specified. These definitions are then assigned a label to allow them to be used in scientific discourse. This article provides a brief guide to help with writing good ontological definitions. The standard format of such a definition is: A is a B that C, or involves or relates to C in some way, where A is the class being defined, B is a parent class and C describes a set of properties of A that distinguish it from other members of B.