FROLIO – Formalizable Relationship-Oriented Language-Insensitive Ontology

Welcome to FROLIO – a new attempt to merge philosophy and the "semantic web". This website is continually under construction - please send suggestions for improvements to the author.

Relationship Major Category - "Classification"

General Meaning

A classification relationship relates two classes, or an instance of a class with that class.

A Class is an abstract concept meaning that there is some level of similarity between instances in the same class. The similarity can be in appearance, properties, past or potential behaviour etc. Wikipedia's definition (accessed 31/05/08) says: “a Class is a collection of sets ... that can be unambiguously defined by a property that all its members share”. A Class should always have a proper definition (axiom) to say which instances qualify and which do not; this axiom may be expressed as a condition, possibly compound. For example, in Australia the class of "Seniors" who get cheaper public transport and various discounts is that one must be over 60 and work less than 20 hours per week.

The potential value for humans is to reason from the Class to the instances of that Class, or to a Sub-class. This is OK up to a point, of course, as in reality there can always be exceptions.

The use of Class as a useful concept must be regarded as originally arising from one or more person's idea, proposition, suggestion etc. It may be suggested that a class exists following a set of observations. This may or may not gain wide consensus among all humans; general acceptability may vary with culture, religion etc. The basis of the classification needs to be clear, as there might be many different dimensions of similarities, e.g. for birds, similarity of shape, similarity of feeding, similarity of genes.

Mathematics and computers - not to mention laws - lean heavily on Classes, but the reality is that many real-life Classes are woolly, arbitrary or contentious. Some people will define a class to support their own agendas. We may deceive ourselves if we think otherwise.

Category Icon

The icon represents the classification of things (people, physical objects or abstract concepts) into categories, as suggested by the pigeonholes.

Relationship Role Diagram (for key to the letter codes click here)

The picture shows the role B (top right) represented as a recycling unit with 3 bins for different categories of waste. It represents the idea of classes to which either the instance A (shapeless "thing" on the left of the second row) or the sub-class A (another recycling bin) are qualified to be categorized. The role C represents the condition determining whether the categorization is justified. The role M represents a process or procedure for testing the validity of the classification. The roles at the bottom of the diagram qualify the assertion that A is an instance or sub-class of B. It may be limited by time or place. It may be the assertion or claim of one or more individual authors Z. It may depend on a theory Y - classification of living things is one example. It may also depend on a context X - a classification scheme may be limited in relevance to one field of study.

	A	C	B
A
			M
P				Z
	T	X	Y

Relationship Types in this Category

There are no sub categories in this category, code "C", which, however is important and fundamental. The things that can be related are not confined to physical objects or substances. They can be procedures, or abstract concepts.

The sole 3 relationship types are:

is an instance of - a thing A is classified, or categorized, as an instance of the category (alias class) B
is a sub-class of, is a super-class of - a category A is regarded as a more specialized version (alias sub-class) of the class B. There are additional conditions that must be met if an instance of B is also to be counted of an instance of A; but all instances of A are automatically also instances of B.
shares some instances with (but not all of either class) - this can be regarded in FROLIO as a general case of the previous type

Examples

Instance
Roger is an instance of Human Beings. Australian Citizens is a sub-class of Human Beings. Fred Nurke is an instance of Ratbags (asserted by Joe Bloggs on 25th April 2007). But what is the definition of the class Ratbags? Fred's mates might not agree.

Sub-class
Elephants are a sub-class of Pachyderms. Pachyderms are a sub-class of Mammals. Mammals are a sub-class of Animals. Barn Owls are a sub-class of what people commonly mean by Owls.

Partial overlap
Australian Citizens shares some instances with UK Citizens - but of course not all Australian Citizens are UK Citizens, and vice versa.

Comments

Complications
Jack and Jill used a condom, Mary used a “morning after” pill, Freda had an early abortion, Maxine had a late abortion, Medusa smothered her baby. To what Class does each thwarted potential adult human belong?

Barn Owls and Tawny Owls are non-overlapping sub-classes of Birds. So are European Magpies and Australian Magpies. But the generally accepted biological classification schemes don't put them in the same classes. Non-specialists class them as Owls or Magpies as they exhibit behaviour and appearance expected of those Classes. The process by which humans name things is often at variance with more systematic classification. Outside of ornithological circles, owls are owls; they hunt at night, make eerie noises and generally behave similarly.

Is an instance of is not quite the same as is a member of
Instance of means that the individuals meet the classification condition (role C). Member of, in FROLIO, means that the thing is part of a collection or assembly of things - which might be all of the same type, or might be all of different types. Of course there may well be a condition on being a member of a collection.

Links to other Categories (these cross-links now fixed!)

Arrangement is in some order with	Classification is a	Distinguishing is different from	Interaction communicates with
Logic is deduction from	Motivation is motivated by	Partitioning is part of	Representation represents
Sensation is experienced by	Transformation is changed from	Utility is useful for	Volition is wanted by