General Formal Ontology (GFO)
should be stated explicitly that values of property universals are not considered
as specialisations of property universals. Properties themselves can be
classified and subdivided in various ways. One natural way to classify
perceptible properties is assigning them based on the way in which they
are perceived. This leads to visible properties (like
lengths and color), smells, tastes (e.g. sweetness, bitterness) and so
However, there are also more formal classification principles for
properties, for instance, according to the categories of the
characterized entities. The following subcategories of properties are
preliminarily distinguished with respect to the
categories their bearers belong to.
Note that for each category a different
subrelation of has-quality may be introduced, in order to integrate
relationships that are fairly established.
- Qualities of material structures, e.g. the color of a ball,
- Qualities of processes, e.g. the average speed of an object's movement, running for half an hour, and
- Qualities of qualities, e.g. a color's hue or brightness.