BS ISO 704:2009 pdf free download – Terminology work – Principles and methods.
5.5.2.2 Generic relations
5.5.2.2.1 Generic relations and general concepts
As mentioned in 5.4.2, the characteristics associated with a concept constitute its intension, and all the objects included in the set of objects associated with the concept constitute its extension. A generic relation exists between two concepts when the intension of the subordinate concept includes the intension of the superordinate concept plus at least one additional delimiting characteristic. For example, the intension of ‘mechanical mouse’ comprises that of ‘computer mouse’ plus the delimiting characteristic having rollers (mechanical sensors) for detecting ball-movement (see Example 2).
In a generic relation, the inclusion relationship between the extensions of the two concepts is the inverse, i.e. the extension of the superordinate concept includes that of the subordinate concept. For example, the extension of ‘computer mouse’ includes that of ‘mechanical mouse’ since some of the objects categorized as computer mice can also be categorized as mechanical mice.
The superordinate concept in a generic relation is called the generic concept and the subordinate concept is called the specific concept.
An important feature of the generic relation is that it assumes inheritance, i.e. if concept B (e.g. ‘mechanical mouse’) is a specific concept of the generic concept A (e.g. ‘computer mouse’), then concept B inherits all the characteristics of concept A. The inheritance principle is a way of testing and validating the generic relationship (see Example 3). In keeping with the metaphor implied by the concept of inheritance, a generic concept is often called a parent, a specific concept is a child, and coordinate concepts are siblings.
When documenting characteristics associated with concepts, instead of listing inherited characteristics redundantly for subordinate concepts, they shall be listed only with the generic concept. Under the specific concept, it is possible simply to list only the additional characteristic(s) that delimits the specific concept from its generic concept and/or from its fellow coordinate concepts. Inherited characteristics can be obtained at the level above in the concept system.
5.5.2.3 Partitive relations
5.5.2.3.1 Partitive relations and general concepts
A partitive relation is said to exist when the superordinate concept represents a whole, while the subordinate concepts represent parts of that whole. The parts come together to form the whole. The superordinate concept in a partitive relation is called the comprehensive concept and the subordinate concept is called the part itive concept. Unlike concepts in a generic relation, concepts in a partitive relation do not inherit characteristics. However, it is important to keep in mind that specific concepts in a generic relation inherit the parts of their superordinate concepts.
The parts that make up the whole may be similar in nature (such as atoms in an oxygen molecule) or distinctly different from each other. One or more parts may be compulsory (and may, in a mixed concept system, be considered characteristics) or optional. Some parts reflect delimiting characteristics in that they allow the whole to be distinguished from other similar comprehensive concepts. Some parts may be multiple such as ‘page’ as part of a book, or variable within a range, such as an ‘ink reservoir’, an ‘ink cartridge’ or an ‘ink refill’ (as part of a pen).