Re: SUO: RE: RE: A proposed SUO content outline
Dear Matthew and Ian,
Every term on your outline is necessary for a complete system
of knowledge representation. Indeed, all of these terms have
been used for many years in mathematics and physics, and they
have been formalized, axiomatized, and reasoned and computed
with in great depth in many different ways for a long time.
The big question is not whether they belong in the SUO. The
answer to that is simple: yes, of course.
Even the issue of writing definitions and axioms for them is
not a big problem. There are plenty of axiomatizations for all
of them that can be taken out of the literature of math, logic,
and physics, dusted off, and translated into KIF, CGs, and
many other notations.
One issue that has to be recognized: all those axioms
were designed for different purposes, and they use very
different primitives. As an example, I use the Eulerian and
Langrangian systems of coordinates for fluid mechanics. Many
of the same phenomena can be represented in either one, but
the representations have very different structures and
relationships. That is true of all those categories in
the outline: there are many, many different coordinate
systems and representations that have been used, all of them
are valuable for different purposes, but the relationships
between them are very far from clear. Taking one coordinate
system instead of another is a purely arbitrary choice, and
you have to know how they are related before you can make
a rational decision about how they should be positioned
in the ontology.
The first thing that has to be determined is which of these
issues belong to the logic, which of them belong to the
ontology, how the logic relates to the ontology, and how
the logic and the ontology relate to the real world and/or
any possible world, situation, state of affairs, etc. And
the next thing is how can you reason about them with the
logic and talk about them with language(s) you want to use.
We all know that the knowledge representation must accommodate
individuals, states, events, space, time, space-time, process,
activity, agents, etc. But you cannot start to put these things
into a hierarchy until you have a very clear idea of what these
things are, how you can refer to them in logic, how they are
classifiable by the ontology (Note: classifiable is a
prerequisite to being classified), and how they relate to
what is in the world, what is perceived by humans, animals,
or robots, how evidence for them is obtained, etc.
Only after these questions are answered, does it become
possible to say where you can position the categories in
the hierarchy, outline, or whatever you want to call it.
Compared to that, questions like the following are a tiny,
insignificant little nit:
>MW: Do you have some things in the merged ontology that are not found here?
>(e.g. holes).
We still haven't answered where the concepts of Circle, Sphere,
and Cube belong. When we know where those belong, then maybe
we can begin to talk about holes in a cube or sphere.
All of Ian's questions about the following list are well taken,
but that is barely scratching the surface of the ones that must
be addressed before we can put these topics into some ordering:
>> > 1. Thing
>> > 1.1. Individual
>> > 1.1.1. State
>> > 1.1.1.1. Period of Time
>> > 1.1.1.2. Activity
>> > 1.1.1.3. Physical Object
>> > 1.1.1.3.1. Materialised Physical Object
>> > 1.1.1.3.2. Functional Physical Object
>> > 1.1.1.3.3. Stream
>> > 1.1.2. Temporal Boundary
>> > 1.1.2.1. Point in Time
>> > 1.1.2.2. Event
>> > 1.2. Collection
>> > 1.2.1. Class
>> > 1.2.1.1. Class of Individual
>> > 1.2.1.1.1. Quantifiable Property
>> > 1.2.1.1.2. Role
>> > 1.2.1.1.3. Status
>> > 1.2.1.1.4. Organisational Level
>> > 1.2.1.1.4.1. Shape
>> > 1.2.1.1.5. Information Pattern
>> > 1.2.1.2. Class of Class
>> > 1.2.1.2.1. Number
>> > 1.2.1.2.2. Class of Relation
>> > 1.2.1.2.2.1. Specialisation
>> > 1.2.1.2.2.2. Unit of Measure Mapping of Property to Number Space
>> > 1.2.1.2.2.3. Class of Representation
>> > 1.2.1.2.2.3.1. Identification
>> > 1.2.1.2.2.3.2. Definition
>> > 1.2.1.2.2.3.3. Description
>> > 1.2.1.3. Relation
>> > 1.2.1.3.1. Classification
>> > 1.2.1.3.2. Cause and Effect
>> > 1.2.1.3.3. Whole-Part
>> > 1.2.1.3.3.1. Fusion Whole-Part
>> > 1.2.1.3.3.2. Arrangement Whole-Part
>> > 1.2.1.3.3.3. Assembly Whole-Part
>> > 1.2.1.3.3.4. Feature Whole-Part
>> > 1.2.1.3.3.5. Temporal Whole-Part
>> > 1.2.1.3.3.6. Participation in Activity
>> > 1.2.1.3.3.7. Temporal Bounding of State
>> > 1.2.1.3.3.8. Containment of Individual
>> > 1.2.1.3.4. Connection
>> > 1.2.1.3.5. Temporal Sequence
>> > 1.2.1.3.6. Involvement in Activity
>> > 1.2.2. Set
Every level of this outline raises very serious questions about
why things are placed on that level, how they are related to
their siblings or their parents and children. Why, for example,
is "period of time" under "state"? What is time? Why is
"cause and effect" a sibling node of "whole-part"? What is
causality? How does causality relate to time? Which is more
fundamental, time or causality? Which one presupposes the
other in its definition? Why?
Having a laundry list of items to be considered is useful.
But without a very serious answer to all these questions,
it should not considered as anything that has any more
structure than a laundry list.
John Sowa