ISKO Italia. Integrative level classification

How ILC works

updated April 2008

 

classes ; free relationship ; facets and categories ; passive facets ; common facets ; place of definition of facets ; subfacets (use of closing bracket); phase relationships ; conjunctions ; spans ; typical subclasses ; deictics, favoured class and special schemes ; viewpoints ; disciplines ; fiction

Classes

Unlike most library classification schemes, ILC classes do not represent disciplines and their subdivisions, but phenomena of the real world.

Phenomena are listed in order of integrative levels. As classes are basically represented by letters, this means that simpler phenomena, like atoms or molecules, are represented by low letters like c, d, e, f, while more complex and integrated phenomena, like societies and cultures, are represented by higher letters such as s, t, u, v:

	...
	d particles
	e atoms
	f molecules
	g bodies
	h celestial objects
	i rocks
	j landforms
	k genes
	l cells
	m organisms
	n populations
	...

Further letters, written in low cases, mean subclasses, namely kinds of their main classes:

	m  organisms
	mf 	mushrooms
	ml 	algae
	mm 	mosses
	mp 	vascular plants
	mq 	animals
	mqm 		mollusca
	mqr 		arthropoda
	mqrh 			crustaceans
	mqri 			insects
	mqv 		chordata, vertebrata
	mqvh 			bony fish
	mqvl 			reptiles
	mqvo 			birds
	mqvt 			mammals

In this way, a longer string means a more specific phenomenon (as in traditional library classifications). At each degree of specificity, whenever possible, phenomena are listed in an evolutionary sequence, or increasing logical depth.

In some (not common) cases, more than 26 subclasses of the same class are needed. Zoology teaches us that Mqvh bony fish has more than 26 subclasses. To cope with this, some less relevant subclasses can be expressed with the "empty digit" z, giving them the same specificity as the adjacent classes, despite having a different number of digits:

	mqvhx 		tetraodontiformes
	mqvhxzf		pleuronectiformes
	mqvhxzs 	scorpaeniformes
	mqvhy 		perciformes

Free relationship

When several phenomena occur together and are considered in generic relationship between each other ("generic phase relationship" or "free relationship"), they can be simply listed together, separated by a blank space (free classification in Gardin's terms). It is usually preferable that they be written starting from the highest integrative level (namely the highest first letter) and going on with more and more low levels, in the reversed order of the schedules:

	mqvt mf hU		mammals : mushrooms : the Earth
	n mqvt      		populations : mammals

Facets and categories

Facets are more specific relationships, representing typical aspects of a phenomenon in connection with other phenomena. Facets of organisms are growth stage (embryo, larva, adult), organs (heart, lungs, kidneys), and sex (female, male); facets of music are players (persons, groups), instruments (drums, guitars, trumpets), and genre (root, jazz, rock).

As these examples show, facets change according to the different phenomena. However, they roughly belong to a limited number of general categories, according to their syntactical relation to the phenomenon (sometimes also described as their role or, in linguistics, their case or complement). General categories, and the corrisponding facets, are represented by numerals (where needed, two or more digits can be used to define a more specific facet):

	0  considered under aspect, modality
	1  at time, in sequence
	2  in location, context
	3  through process, transformation
	4  of material, constituents
	5  with organs, parts
	6  by factor, origin
	7  for function, to destination
	8  having pattern, like, about topic
	9  of kind, quality

In music, players are agents, hence they are facet 6:

	xm music
		xm6 music by player...
			xm6{beatles} music played by the Beatles
			xm6{radiohead} music played by the Radiohead
(As players are usually individual humans or groups identified by a name, the name itself can be used as a subclass. In this case it is written between {}, not to be confused with subclass b, sub-subclass be, sub-sub-subclass bea, etc.)

In animals, geographical distribution is a location, hence it is facet 2:

	m  animals
	m2 	animals with distribution
	m2e 		animals distributed in Europe
	m2o 		animals distributed in Oceania

while sex is one possible form of the organism, hence it is facet 9:

	m  organisms
	m9 	of sex
	m9f 		females
	m9m 		males

Facets of a given class also hold for all its subclasses:

	mqm9f   female mollusca
	mqri9f  female insects
	mqvl9f  female reptiles

(unless another facet of the same category is defined at a subclass, so that they are cascading facets holding at different degrees of specifity).

When more than one facet are expressed for the same phenomenon, they should be cited in the reversed order of numerals, according to the inversion principle: as 9 is greater than 2,

	mqvl9f2e  female reptiles in Europe

Only when a subject is discussed focusing especially on one aspect, the corresponding facet can be moved before another despite the standard citation order:

	mqvl2e9f  European reptiles, female

The value of a facet can sometimes be left unexpressed. This can be done by a capital X after the facet indicator:

	mqvl2X  reptiles in some region

X is a deictic meaning "some".

Passive facets

Reversed relations, i.e. passive facets, can be obtained by prefixing 9 to the facet digit:

	u6v		economies influenced by technologies
	v96u		technologies influencing economies

They are used to put the central topic of a document first:

	n9qvtniok	populations of killer whales
	o9vtniok	behaviour of killer whales
	mqvtniok99n99o	killer whales: their populations and behaviour

as in "Ross sea killer whale distribution, behavior, color pattern, and vocalizations", a 1981 book by JA Thomas et al. classified in BARD.

Common facets

The meaning of some facets is appliable in any main class: geographical location can be a facet of any phenomenon, as can causation. These common facets are defined at the most general degree, and keep their meaning in all subclasses, except where a more specific meaning is defined (respecting the principle of cascading facets). You don't need to find it in the schedule of a specific class to apply it, as they are applicable throughout the whole scheme. (In other general classifications they are called "common subdivisions" or "common auxiliaries".)

Most general facets are expressed by just one digit, while more digits represent a more specific meaning which is a combination of the corresponding categories: 16 means "originated/born at time", as 1 means "at time" and 6 means "from factor or origin". Multi-digit facets beginning with 8 are used to express passive facets.

The list of common facets can be seen by browsing the coloured categories on the right of the schedules main page.

In classes where specific facets are defined for the same category, in order to avoid ambiguity, common facets have to be written after a closing bracket:

	2 [jU]		in region (common facet)
	jUe		European region
	2e		in the European region

	u2 [tnU]	economies in country
	u2e		Italy
	u2e		economies in Italy
	u)2e		economies in the European region

Place of definition of facets

In some cases, the meaning of facets is self-defined at the same integrative level where they occur, called their place of unique definition: for example, sex is defined as such at the level of organisms themselves, while at lower levels like rocks or atoms they are nonsense (atoms cannot be female or male!). To express this, the symbol [:] is found in the schedules:
	m     organisms
	m9 [:]    sex
	m9f 		female
	m9m 		male

In other cases, however, the values of facets are taken from a different level of phenomena. Music players are always humans, they cannot be atoms or rocks. So the facet of players in music is defined outside the class of music. Let's take another example: breeding always use as its material some animal: there are no tame rocks or tame trumpets, only tame animals. Hence facet 3 (material) of vd pastoralism always is some animal mq, and in the schedules is written

	vd       pastoralism
	vd4 [mq] 	breeding tame species

This means that subclasses of facet vd4 are the same as subclasses of mq, and their notation must be taken from mq (technically, they can be called extra-defined foci, instead of context-defined foci as in the previous example):

	m  organisms
	mq 	 animals
	mqv 		vertebrates
	mqvo 			birds

	vd4 [mq]  breeding tame species
	vd4v 		breeding vertebrates
	vd4vo 		breeding birds

In case the related class is unusually not a subclass of the foreseen class, its notaton will be written in brackets:

	vd4(le)		breeding bacteria

Finally, some facets provide for relation with any other possible phenomenon in the schedules. Take knowledge. It has an object, which can be expressed by facet 8:

	y     knowledge
	y8 [*] 		knowledge about object

Actually, knowledge can have any object, so its notation can be built by combination with any other part of the schedules. This fact is expressed by the symbol [*].

	y8e    knowledge about atoms
	y8mqvo knowledge about birds
	y8xm   knowledge about music
	y8y    knowledge about knowledge

Use of closing bracket

As a consequence of the place of definition, when a class is the subclass of a faceted concept, it must be introduced by ). Consider this case:

	q5 [o5]	communication through channel
	q5h	acoustic communication

We now want to have the notation for vocal communication, which is a subclass of acoustic communication. However, if we would use q5hv, that would mean "communication through channel o5hv", which is a different meaning. Instead, to express the fact that vocal communication is a subclass of the whole faceted class q5h, we have to write

	q5h)v	 acoustic communication

Subfacets

y also has other facets, including

	y6 [U] knowledge from teacher...

Now, suppose that we have to build the classmark for "knowledge of music played by the Beatles". Component notation is

	xm6{beatles}	music by the Beatles
	y8 [*] 		knowledge about object

but if we simply put them together, we get

	y8xm6{beatles}

which can be interpreted as "knowledge about music, taught by the Beatles" as facet 6 of y means teachers of knowledge. What we want to express, instead, is that knowledge is about an object consisting of "music played by the Beatles". To avoid this ambiguity, we must express that 6 is a subfacet of facet 8, not a facet of y; subfacets are written in round brackets:

	y8xm(6{beatles}) knowledge of music played by the Beatles

When indexing deeply specialized documents, the nesting of subfacets can become very complicated: a document entitled "Guidelines on the applications of the environment protection and biodiversity conservation act to interactions between offshore operations and larger cetaceans" would be

	v8ve48mqvtn(802o68t(3)25c)4d

To make notation less awful and easier to parse by both humans and computers, it can be "flattened" by writing some facets as separate terms introduced by free relationship:

	v4d8 ve48 mqvtn802o68t(3)25c

Here, ending facet indicators 8 and 48 refer to the whole subsequent phase, thus avoiding most brackets.

Phase relationships

Relationship sometimes occur between complex concepts, each possibly including facets or other relations. In this case, the two related concepts (called the phases) are grouped in brackets, and connected by the appropriate category digit. Opening bracket of the first group is omitted:

	u2e		economies in Italy
	y8v		knowledge of technology

	u2e)6(y8v)	economies in Italy influenced by knowledge of technology

Likely used phase relationships are:

	)(   general phase relation, coordination
	)1(  at time
	)2(  in region
	)3(  through process, mechanism
	)4(  with parts
	)5(  with components, organs
	)6(  influenced by
	)68( interacting with
	)7(  applied to
	)8(  compared to
	)934( as a mean for
	)96( influencing, impacting on

)( is a generic phase relationship, similar in meaning to free relationship, as no specific kind of relationship is expressed:

	u2e)(y8t)	economies in Italy related (in some way) to knowledge of technology

Sometimes a phase relationship, such as u n "economy in relation to population", can be nested within a facet. In this case, expressing it by a blank space such as in

	y8u n knowledge of economy : populations ??

would yield a problematic classmark, as n would be parsed as a separate class. To avoid this, within a faceted classmark, the related class is expressed in brackets. Hence

	y8u(n) knowledge of economy in relation to population

To summarize it, two classes aaa and bbb can stay in these relationships [Gnoli 2007d]:

	aaa bbb		free relationship	  		(free classification sensu Gardin)
	aaa)6(bbb)	phase relationship	  		(freely-faceted classification sensu Austin)
	aaa(6bbb)	common facet		  		(faceted classification)
	aaa6bbb		cascading facet defined within class a 	(faceted classification)

Conjunctions

Two or more classes sharing the same syntactical role can be listed in the same order of schedules and glued by the symbol W (or &):

	iWm 	rocks and organisms

This can also happen within a facet:

	y8i   	knowledge of rocks
	y8iWm 	knowledge of both rocks and organisms

By default, symbol W introduces a sister class, i.e. a class sharing all letters except for the last one, so that abcdWx means "abcd together with abcx". To list non-syster classes, W must be followed by another upper case, which means the number of letters shared with the previous class, starting to count from the beginning of the classmark:

	abcdWAx = abcd together with x
	abcdWBx = abcd together with ax
	abcdWCx = abcd together with abx
	etc.

Spans

A consecutive series of classes can be expressed by connecting the notation of the first and the last of them by the symbol V (or %):

	jVm  = jWkWlWm	rocks and genes and cells and organisms

When used in subclasses, by default it introduces a sister class, like in the case of conjunctions:

	mlVp  = mlWmmWmnWmoWmp	algae and mosses (and ...) and vascular plants

Analogously, to include non-syster classes, V must be followed by a deictic, which means the number of letters shared with the previous class, starting to count from the beginning of the classmark:

	abcdefVAg = abcdef to g
	abcdefVBg = abcdef to ag
	abcdefVCg = abcdef to abg
	abcdefVDg = abcdef to abcg

Typical subclasses

Some phenomena are of particular interest to human knowledge. Among all organisms, Man is obviously the most interesting and studied in human knowledge. As an anthropoid primate mammal, its complete notation would be something like mqvtphh; but it is helpful that this long notation be shortened, and Man is listed first among organisms as the one most frequently discussed. To this purpose, the class U "the typical" is used as a differentia, meaning "that which we all have in mind":

	h  celestial objects
	hU  	 the Earth

	hk  stars
	hkU 	 the Sun

	k  landforms
	kU = k2(hU)1h  landforms of the Earth in Holocene (contemporary era)

	U = mqvtphh  people, humans

Deictics, favoured class and special schemes

Some concepts change their meaning according to the context. Examples are the concepts of "next", "tomorrow", "here", "you"... The meaning of "tomorrow" depends on which day is it today; the meaning of "you" depends on whom am I speaking together. These concepts are called deictics and in ILC are represented by upper-case letters (previously Aa, 98, @). Thus:

	cb  time
	cbU 	 now

	AM  I, we
	AO  you

A to T are the favoured host classes or the domain of discourse. They represent the focus phenomena of concern in the present context. This is useful when most expressed knowledge is about a specific domain, so that a special classification scheme can be used instead of the general one. All classes beginning with A ... T are subclasses of the favoured class, either taken from the general schedules (lower case letters, e.g. Abcd), or in turn locally defined (capital letters, e.g. ABCD).

For example, the Dandelion bibliography of facet analysis mostly concerns subject indexing, its subclasses and its facets. In the general ILC schedule there is

	y  knowledge
	yi 	indexes, catalogues
	yis 		subject indexes, knowledge organization systems
	yis3 [:] 		indexing methods, systems
	yis3e 			enumeration
	yis3f 			facet analysis
	yis3l 			level analysis
	yis5 [:] 		elements
	yis5n 			controlled terms
	yis5s 			subject strings
	yis5t 			notation
	yise 			keyword indexes
	yish 			term indexes, thesauri
	yisj 			subject headings
	yisl 			systematic indexes, classifications, taxonomies
	yiso 			semantic networks, ontologies

Hence most references in the bibliography should be classified by subclasses and facets of yis. To get a shorter notation, and to get the preferred topics at the beginning of lists, yis is stated to be the preferred class A:

	A  subject indexes, knowledge organization systems
	A3 	by indexing methods, systems
	A3e 		enumeration
	A3f 		facet analysis
	A3l 		level analysis
	A5 	with elements
	A5n 		controlled terms
	A5s 		subject strings
	A5t 		notation
	Ae 	keyword indexes
	Ah 	term indexes, thesauri
	Aj 	subject headings
	Al 	systematic indexes, classifications, taxonomies
	Ao 	semantic networks, ontologies

Y means individual instances of a class: mqY are individual animals, tnY are individual countries, etc. Individuals have no subclasses in the proper sense. Thus, further letters usually mean parts of them:

	tnY	individual countries
	tnYa	country A
	tnYab	district B of country A

Deictics can also be used in combination: AVD "A to D", YX "what individual".

Viewpoints

The scheme of phenomena in ILC is intended to be as objective and neutral as contemporary knowledge allows. Of course, one could always claim that this is only one among many possible views of the world, as it happens in any classification; anyway, the scheme is being developed with an effort towards neutrality.

Sometimes, however, there is a need to reflect different and particular viewpoints in classification -- that is, of viewpoint warrant, as Begthol terms it. Examples are the alternative orderings in knowledge of indigenous people, of non-Western traditions, of adepts of some faith or theory, of children, or schemes for special purposes. In the general scheme of ILC, they will usually fall under classes v "cultures" and y "knowledge":

	mq  	animals

	y  	knowledge
	y8  	knowledge of object
	y8mq  	knowledge of animals
	yd  	traditional knowledge
	yd8mq 	traditional knowledge of animals
	yg  	magic
	yg8mq 	magical knowledge of animals
	yn  	science
	yn8mq  	zoology

A most classical example reported by Borges and Foucault is the weird classification of animals in a Chinese encyclopedia entitled "Celestial emporium of benevolent knowledge". It will fall under something like

	ydx  ancient Chinese cultures
	ydxx  	ancient Chinese culture X
	ydxx8mq  		ancient Chinese culture X dealing with animals

Now, subclasses of ydxx8mq do not follow a contemporary scientific classification like

	ydxx8mqb  poriphera
	ydxx8mqc  cnidaria, coelenterata 
	ydxx8mqd  ctenofora
	[etc.]

but a very idiosyncratic system, which can be expressed after a closing bracket, as it is a subclass of this particular combination of facets:

	ydxx8mq)a  animals that belong to the Emperor 
	ydxx8mq)b  embalmed animals
	ydxx8mq)c  animals that are trained
	ydxx8mq)d  suckling pigs
	ydxx8mq)e  mermaids
	ydxx8mq)f  fabulous animals
	ydxx8mq)g  stray dogs
	ydxx8mq)h  animals included in the present classification
	ydxx8mq)i  animals that tremble as if they were mad
	ydxx8mq)j  innumerable animals
	ydxx8mq)k  animals drayd with a very fine camelhair brush
	ydxx8mq)l  other animals
	ydxx8mq)m  animals that have just broken a flower vase
	ydxx8mq)n  aninals that from a long way off look like flies

A knowledge base organized according to this system could be indexed by these classmarks. As the initial sequence ydxx8mq) occurs in the majoirity or totality of cases, it can be shortened by upper-case letters, giving

	A  animals that belong to the Emperor
	B  embalmed animals
	C  animals that are trained
	D  suckling pigs
	[etc.]

In cases where the studied phenomenon is more relevant than the viewpoint, notation can be reversed to give priority to the phenomenon:

	mq98ydxx  animals according to ancient Chinese culture X
	mq98ydxy  animals according to culture Y

The sequence 98y, meaning "being topic of culture", can be substituted by the common facet 06 [v9]:

	mq06nxx  animals according to ancient Chinese culture X
	mq06ny   animals according to culture Y

A similar device can be used also to express the method of study (y3) in Szostak's favoured sequence of phenomenon, theory, and method:

	mq03b  	 animals studied through observation
	mq04y03b animals according to theory Y studied through observation

and for Vickery's activities:

	mp07va	plants studied for health applications		
	mp07wa	plants studied for food applications

Disciplines

One particular viewpoint which is often adopted is that of academic disciplines studying phenomena. Although ILC classes represent phenomena instead of disciplines, the latter can be represented as a kind of phenomena, at the integrative level of knowledge:

	y  knowledge
	y8 	of object
	yn 		sciences
	ynd 			physics
	ynf 			chemistry
	ynh 			geology
	ynl 			biology
	ynl8yr 				biology of forests
	ynq 			linguistic
	ynr 			sociology
	ynu 			economics
	ynu8yr 				economics of forests

If now we set yn as the favoured class A, we obtain a discipline-based scheme similar to those of traditional bibliographic classifications:

	Ad 	physics
	Af 	chemistry
	Ah 	geology
	Al 	biology
	Al8nyr 		biology of forests
	Aq 	linguistic
	Ar 	sociology
	Au 	economics
	Au8nyr 		economics of forests

Fiction

While works about literature, cinema, etc. must be classified in xl, xs etc., works of literature and cinema must not; indeed, they are not about arts, but are in form of art [Kyle 1959]. So, what are they about?

In most cases, literary works are about topics related with people and society, in a more or less fictional set. Thus, they can be classified as pg08i "imaginary personalities", or s08i "imaginary communities", etc., depending on what level is the focus one. 08i will not apply to e.g. documentary films.

For example, Maigret novels mainly deal with murders t70d, and the emotions and personalities p of people involved in them, in 20th century t1j France tnUc; thus, they can be classified as tnUc70d68p1j08i. If author is relevant, it can be expressed: tnUc70d68p1j08i006{simenon}. If one wants to account for the document being a video adaptation of Simenon novels, the 00v carrier suffix can be added. Wim Wender's film "The American friend" deals with friendship pew by a fictional story set in Germany 0829b in form of moving images 00v; thus, it can be classified as pew08i0829b00v.

On the other hands, if the form is considered to be more relevant than the contents, like in a collection of poems on very disparate subjects, the classmark can consist only of formal facets: 0040h003eir "poems in French".

 


How ILC works / [Claudio Gnoli] = (ISKO Italia. ILC) – <http://www.iskoi.org/ilc/how.htm> : 2005.08.04 - 2008.06.06 -