Building a faceted classification Fundamentals of facet analysis

Fundamental structures in classification schemes: • enumerative schemes (LCC, DDC) • analytico-synthetic schemes (UDC, BC 1) • faceted schemes (CC, BC 2) Vanda Broughton, School of Library, Archive & Information Studies, UCL

Enumerative schemes: • list all the possible classes • high levels of pre-coordination of concepts • very few possibilities for building classmarks • scheme is not hospitable to new topics or concepts Vanda Broughton, School of Library, Archive & Information Studies, UCL

Enumerative classification structure in LCC: Vanda Broughton, School of Library, Archive & Information Studies, UCL

Analytico-synthetic schemes: • analytico-synthetic schemes are half-way between enumerative and faceted classifications • have auxiliary or systematic schedules • have facilities for compounding classes • may contain pre-coordinated headings, as well as simple concepts Vanda Broughton, School of Library, Archive & Information Studies, UCL

Faceted classifications: • are rigorously structured • list only simple concepts • build classmarks as and when required • combination is much more extensive Vanda Broughton, School of Library, Archive & Information Studies, UCL

Indexing languages: • indexing languages (such as classifications) consist of: • a stock of vocabulary (the concepts or classes) • rules for combination of words (the system syntax) Vanda Broughton, School of Library, Archive & Information Studies, UCL

Indexing languages require: • rules for organizing the concepts • rules for joining the concepts together Vanda Broughton, School of Library, Archive & Information Studies, UCL

Organization of concepts: • traditional methods use pragmatic techniques • the idea of a subject domain may be used • often concepts in a subject are just clustered together • this method is used in concept or topic maps • they’re visually representative but lack logical structure Vanda Broughton, School of Library, Archive & Information Studies, UCL

Vanda Broughton, School of Library, Archive & Information Studies, UCL

‘Ontological’ relationships: Vanda Broughton, School of Library, Archive & Information Studies, UCL

What is ‘classical’ facet analysis: • a means of organizing the concepts in a subject domain • involves grouping concepts on the basis of shared characteristics • uses standard categories as ‘receptacles’ for concepts • in ‘classical’ facet analysis these are linguistic/functional categories Vanda Broughton, School of Library, Archive & Information Studies, UCL

Types of categories used: • earliest set of categories was that of Kaiser (1911) • these were used in alphabetical subject indexing to generate pre-coordinated headings • concretes (= things/entities/substances) • processes (= activities/actions) • place • coal – • (concrete) – • banks mining (process) – Brazil – (place) – administration – Europe Vanda Broughton, School of Library, Archive & Information Studies, UCL

Ranganathan’s categories: • personality (= entities or systems) • matter (= substances) • energy (= actions or activities) • space • time Vanda Broughton, School of Library, Archive & Information Studies, UCL

UK Classification Research Group categories: an expansion of Ranganathan’s PMEST: • • thing kind part property material process operation • • • patient product by-product agent space time Vanda Broughton, School of Library, Archive & Information Studies, UCL

These categories have been used in all classes in the second edition of the Bliss Bibliographic Classification (BC 2): • they work well for concepts in most subjects • they work best with science and technology • not every category is needed in every subject • some additional categories are needed in the arts e. g. form and genre Vanda Broughton, School of Library, Archive & Information Studies, UCL

Application of facet analysis standard categories to horticulture: • • • things kinds parts properties materials process operation product agent space time = = = plants trees, flowering plants, mosses, fungi petals, roots, fruit, leaves green, poisonous cellulose, xylem, pigments germination, growth, fruiting cultivation, pruning, harvesting fibres, foodstuffs, drugs spades, tractors, fertilizers, gardeners Brazil, tropics, dry areas nineteenth century, weekend Vanda Broughton, School of Library, Archive & Information Studies, UCL

Organization into arrays: • the large number of concepts in a category or facet means that they need to be organized into subgroups called sub-facets, or arrays • an array = a set of terms whose members represent various examples or ‘values’ of a particular attribute • characteristic (or principle) of division) = the name of this shared attribute

Arrays in organs facet in medicine: (Parts of the body by region) (Parts of the body by function) Head Neck Body, torso chest abdomen Limbs legs wings Locomotor system Circulatory system Digestive system Nervous system

Arrays in the place facet: (by orientation) North South East West (by temperature) tropics temperate zones arctic (by physiographic features) hills plains forests seas

Modelling a subject domain: • categorization alone does not make a faceted system • it must also deal with the order of, and relationships between, concepts • attention should also be paid to sequence or order of concepts in combination • the last is less vital in a digital context, but still important where any sort of linear order or display is needed Vanda Broughton, School of Library, Archive & Information Studies, UCL

Organization within groups: • simply grouping similar concepts won’t create a classification • each set of concepts must be ordered • various pragmatic orders can be adopted as appropriate e. g. chronological, geographical, developmental • this is particularly important for physical arrangement, but is also relevant for browsing and for displaying search results • a classification must also demonstrate the relationships between concepts Vanda Broughton, School of Library, Archive & Information Studies, UCL

Hierarchical relationships: • the most basic relationship in a classification is that of hierarchy • this relationship is expressive of classes and their subclasses • this is sometimes also referred to as subordination and superordination • the relationship is usually represented visually in the classification display Vanda Broughton, School of Library, Archive & Information Studies, UCL

Hierarchy showing subordinate and superordinate classes through indentation: Birds Parrots Macaws Polly Vanda Broughton, School of Library, Archive & Information Studies, UCL

This can also be represented as a logical diagram: birds parrots macaws Polly Vanda Broughton, School of Library, Archive & Information Studies, UCL

Hierarchical relationships: • true hierarchical relationships are those in which the subordinate class is wholly contained by the superordinate class • there are three main types: • thing-kind or genus-species (sometimes called generic or taxonomic relationships) • whole-part (sometimes called partonomic) • instantive (or instantial) relationships between a class and an individual named member of the class Vanda Broughton, School of Library, Archive & Information Studies, UCL

Thing-kind deals with an entity and its varieties or types (species): Cheese Wensleydale Camembert Stilton Rodents Rats Mice Gerbils Spaniels Springer spaniels Cocker spaniels Water spaniels Vanda Broughton, School of Library, Archive & Information Studies, UCL

Whole-part deals with an entity and its constituents or components: Europe France England Spain Flowers Stamens Petals Sepals Atoms Protons Neutrons Electrons Vanda Broughton, School of Library, Archive & Information Studies, UCL

Instantive relationships are between a class and its individual members: Mountains Mount Everest Kilimanjaro Fujiyama Artists Leonardo da Vinci Braque El Greco Canaries Tweetie-pie Vanda Broughton, School of Library, Archive & Information Studies, UCL

Relationships in a hierarchy: • a hierarchy or taxonomy shows relationships that are: – superordinate – subordinate – coordinate • these hierarchical relationships are also often called: – semantic; or – paradigmatic • they are permanent relationships between the concepts in a subject field • they are usually indicated by indentation of successive sub-classes • sometimes a concept can occur in different hierarchies Vanda Broughton, School of Library, Archive & Information Studies, UCL

Vanda Broughton, School of Library, Archive & Information Studies, UCL

pets pet parrots Vanda Broughton, School of Library, Archive & Information Studies, UCL parrots

Other relationships between concepts: • otherwise unrelated concepts can be brought together in a compound subject e. g. ‘teaching classification’ • such relationships are known as syntagmatic relationships Vanda Broughton, School of Library, Archive & Information Studies, UCL

Wheat harvesting using combine harvesters wheat harvesting combine harvester Vanda Broughton, School of Library, Archive & Information Studies, UCL

Paradigmatic and syntagmatic relationships: name Paradigmatic relationships between terms contained in the vocabulary entities operations agents cereals plant husbandry farm machinery wheat harvesting combine harvesters Syntagmatic relationships between terms assigned to a document Vanda Broughton, School of Library, Archive & Information Studies, UCL

Relationships in bibliographic classifications: • how individual classifications manage relationships differs considerably • early bibliographic classifications are not very well structured • only in the mid-twentieth century was theory of classificatory structure developed • modern classifications are more logical in their construction • this is significant for machine management and for automated searching and indexing Vanda Broughton, School of Library, Archive & Information Studies, UCL

Ontology with concepts and relationships: Vanda Broughton, School of Library, Archive & Information Studies, UCL

Faceted approach with categorized concepts: does lives in Vanda Broughton, School of Library, Archive & Information Studies, UCL wears

Relationships between concepts can be expressed in different ways: • through facet indicators • through relationship indicators • through the sequence of concepts, or citation order • different faceted languages utilise all of these methods Vanda Broughton, School of Library, Archive & Information Studies, UCL

Rules for joining concepts together in language (syntax): • sometimes meaning is achieved by inflection: • homo mordet canem • canis mordet hominem § o anqrwpo. V esqiei ton kuonta § o kuwn esqiei ton anqrwpon Vanda Broughton, School of Library, Archive & Information Studies, UCL

Sometimes meaning is achieved by word order: • man bites dog • dog bites man • man eating sausage Vanda Broughton, School of Library, Archive & Information Studies, UCL

Indexing languages can function in both of these ways: • some (like PRECIS, or UDC) use role operators = symbols which indicate their status • others (like BC 2) rely on order in the schedule to give meaning to the components Vanda Broughton, School of Library, Archive & Information Studies, UCL

Facet indicators (role operators) in UDC: Vanda Broughton, School of Library, Archive & Information Studies, UCL

Relational operators in indexing systems: • Farradane’s system • Clamping of hardened steel plates • steel /: plates /- clamping /; hardening • /: causation or dependence • /- reaction • /; association Vanda Broughton, School of Library, Archive & Information Studies, UCL

In many modern faceted systems the means of combining terms is controlled by the citation order: • citation order is the order of categories with which we’re familiar • i. e. thing - kind - part - etc…. • this is the so-called ‘standard’ citation order • facet status determines the combination, but this is implicit in the notation • it’s a good guide to the best default order of combination, but isn’t immutable Vanda Broughton, School of Library, Archive & Information Studies, UCL

Examples of standard citation order in horticulture: • Winter pruning of roses • roses (entity) + pruning (operation) + winter (time) • Machine harvesting of Brussels sprouts • Brussels sprouts (entity) + harvesting (operation) + machine (agent) Vanda Broughton, School of Library, Archive & Information Studies, UCL

The Colon Classification: • uses the fundamental categories (P M E S T) • uses facet indicators in the form of punctuation symbols to denote the categorical status of a concept • . T. S : E ; M , P • uses a facet formula to combine and express complex content • l [P] [P 2] [P 3] : [E] 2 P : [2 E] • Y [P] : [E] : [2 E]. S. T Vanda Broughton, School of Library, Archive & Information Studies, UCL

Modelling data: traditional models • Ranganathan compared faceted schemes to engineering toys like Meccano • a modern equivalent is Lego • the idea is that the structure is assembled from small components

Molecular models as a pattern: • molecular modelling provides a useful modern equivalent to Ranganathan’s Meccano analogy • molecular systems also try to represent: • the nature of the components • the relationships between them • their relative positions • internal and external relationships between particles • a syntax or rules for combination Vanda Broughton, School of Library, Archive & Information Studies, UCL

Vanda Broughton, School of Library, Archive & Information Studies, UCL

Revision of BC and the second edition: • the British Bliss Classification Committee became the Bliss Classification Association • funds were raised for a revision programme to be carried out under the editorship of Jack Mills • the revision was to be radical and to incorporate faceted classification principles • the work was carried out at the Polytechnic of North London Library School • much was contributed by BC users, and by members of the profession, particularly the CRG • the schedules began to be published in the 1970 s Vanda Broughton, School of Library, Archive & Information Studies, UCL

Features of BC 1 carried into BC 2: • built on theoretical principles • the most scholarly of the general schemes • the best main class order • takes account of educational consensus and literary warrant • provision for synthesising classmarks for compound subjects • many alternative treatments and locations Vanda Broughton, School of Library, Archive & Information Studies, UCL

New features of BC 2: • a greatly expanded and modernised vocabulary • the imposition of a rigorously faceted structure, with clear articulation of the facet structure • the use of a synthetic and retroactive notation • a detailed alphabetical index • introductory material explaining the principles on which the scheme was built Vanda Broughton, School of Library, Archive & Information Studies, UCL

Standard categories as used in BC 2: • • • • thing, entity (the major object, or end-purpose, of the discipline) kind (varieties of the thing) part (constituents or components) property (attributes, characteristics) material (substances of which things are made) process (actions which occur by themselves) operations (actions performed by an external agent) patient (the recipient of an action other than the entity) product by-product agent (person or equipment by which operations are performed) space time Vanda Broughton, School of Library, Archive & Information Studies, UCL

Categories in zoology: • • thing kind part property processes operations agents • space • time organisms, animal (wolf, amoeba, butterfly, frog) sorts of animals (wild animals, farm animals) organs and systems if the body (heart, legs, nerves) attributes, characteristics (carnivorous, furry) what animals so (breathe, grow, reproduce) what is done to animals (observation, dissection) means of performing operations (biologists, wildlife wardens, microscopes, binoculars) places (Africa, deserts, forests) period (twenty-first century, future) Vanda Broughton, School of Library, Archive & Information Studies, UCL

Fundamental category subject specific facet: • the thing category the organisms facet • the part category the organs and systems facet • the space category the place facet Vanda Broughton, School of Library, Archive & Information Studies, UCL

Organization into arrays: • an array = a set of terms whose members represent various examples or ‘values’ of a particular attribute • characteristic (or principle) of division) = the name of this shared attribute Vanda Broughton, School of Library, Archive & Information Studies, UCL

Arrays in organs facet: (Parts of the body by region) (Parts of the body by function) Head Neck Body, torso chest abdomen Limbs legs wings Locomotor system Circulatory system Digestive system Nervous system Vanda Broughton, School of Library, Archive & Information Studies, UCL

Order of facets in schedule (inverted schedule): • • • time place agents operations processes materials parts kinds things Vanda Broughton, School of Library, Archive & Information Studies, UCL

The order of facets can be repeated at any point: Time Place Agents Operations Agents of operations Processes Parts Processes of parts Kinds Things Operations on things Processes of things Parts of things Operations on parts of things Agents of operations on parts of things Processes of parts of things Vanda Broughton, School of Library, Archive & Information Studies, UCL

Vanda Broughton, School of Library, Archive & Information Studies, UCL

The use of pre-combined terms in scheduling (examples of combination): • it aids the cataloguer or indexer in locating compounds • it correctly locates compounds with unique names e. g. ‘arthritis’ as ‘joints – inflammation’ • it facilitates the inclusion of such terms in the alphabetical index Vanda Broughton, School of Library, Archive & Information Studies, UCL

Retroactive notation in practice: Vanda Broughton, School of Library, Archive & Information Studies, UCL

Published classification schedule from BC 2: Vanda Broughton, School of Library, Archive & Information Studies, UCL