ISKO 2010, Rome, 23-26 Feb 2010

Workshop on Levels of reality as a KO paradigm

Levels, types, facets: three structural principles

for KO

Claudio Gnoli(University of Pavia)

Levels of reality

• How levels are used as a structuring principle in KOSs ?

• How levels interact with other structuring principles ?

Structuring principles in KOSs

• Types• Facets• Levels• (Aspects)• (Dimensions)• (...)

Typesforming “Porphyrian” hierarchical trees of:

genera/differentiae ~classes/subclasses ~BTs/NTs ~X is_a Y

increasing specificity,depth,“level”

Facets

P M E S ...

a.k.a. “attributes”, “values”, “slots”, ...

RT (several kinds) ~X has Y

belonging to general categories:

standardcitation order

Levels. 1

a.k.a. “great chain of being”, “scala naturae”, “emergent evolution”...

X depends_on Y (asymmetrical!)

increasing organization,

often also complexity

series, “hierarchy”

of lower/higher levels

Levels. 2

strata: matter < life < mind < culture (building-above rel.)

layers: cells < organisms < populations (overforming rel.)

[N. Hartmann’s ontology]{

Levels. 3Less often acknowledged in KO, still common, especially for main classes:• Roget’s Thesaurus• Brown’s Subject Classification• Richardson’s classification theory [Dousa, this conf.]• Bliss’s Bibliographic Classification• Wåhlin’s Universal System• Scheele’s Universal Facet Classification• Dahlberg’s Information Coding Classification

Explicitly acknowledged by D.J. Foskett for CRG’s NATO project of a phenomenon classification,resumed by the ILC project

Levels. 4

produce arrays (ordered sets) of main classes:

... physics < chemistry < biology < sociology ...

or of subclasses:

morphemes < words < phrases < sentences < discourses

families < groups < cities < nations < int. org.s

The problem of priority

Which principle should come first in KOSs?

Do we need• levels of types?• facets of levels?• types of facets?...

Types, then levels

LCC, DDC, UDC: ... 1 philosophy 2 religion 3 social sciences 5 natural sciences

51 maths52 astronomy53 physics54 chemistry...

Epistemological approach

Levels, then types

Brown’s SC,Bliss’s BC1

“gradation by speciality”

Ontological approach

Types, then facets

Colon Classification

each type is an isolated domain with its own facets

Facets, then types

specialthesauri &classifications

NuovoSoggettario:the world is divided into Things, Properties, Activities, Time

Levels, then facets. 1

BC2ICC (recursive facets!)

CRG’s NATO project, ILC

levels are “categoricallyhomogeneous regions”[Poli]

“Mr Foskett suggested that Energy isolates for a general

classification should be sought in the first place in the

literature dealing with a particular Thing. It might be

found that a given activity was associated [...]

with all Things at the same integrative level, or

even with all Things at all levels. Only the last

should be regarded as isolates in the category of

Activities [...]. Each such differential Activity might be

placed in linear order before the single Thing, group

or level of Things with which it was exclusively

associated” [CRG 1961]

Levels, then facets. 2

Facets, then levels. 1

Austin’s version of NATO cl.,?Nuovo

Soggettario

physiology under Activities butorganisms under Things...

Facets, then levels. 2Current work in NS [Cheti, Lucarelli et al.]

management <economics>management <politics> ...

Which is management’s place of unique definition?Let’s list each concept only once. Levels provide a useful model:

Activitiesmaterial activitiesmental activitiessocial activities

...

KO evolution?

• Types are the most classical principle in KO

• Facets are now also classical

• Levels have been acknowledged later, but often act implicitly,already since “scala naturae”

Conclusions

• New KOSs, including ontologies,show poor awareness of levels

• exception: General Formal Ontology [Herre et al. 2006]

• Explicit analysis of levelscontributes to both KO theory and sound KOS structure

...thank you

from <flickr.com/photos/_leonid/277933222>

comments welcome <gnoli@aib.it>