Classification Design
Creating subject languages
INF 384 C, Spring 2009
Outline
• What is being represented? Defining the
domain of representation.
• What overall structure best fits the domain?
Determining the general form of the subject
language.
• How should concepts be arranged within the
structure? Ordering concepts at each level of
the classification.
INF 384 C, Spring 2009
Defining a subject domain
A subject language represents a domain of knowledge
as a system of related concepts.
Last week, for example, you decided that “lawn
maintenance” and “sustainable urban gardening in
Austin” were represented by a particular group of
concepts.
But how do you determine what “lawn maintenance” is?
INF 384 C, Spring 2009
Defining domains as discourse
communities
Hjorland and Albrechtsen argue that information
systems should be based on discourse
communities of academic disciplines.
Psychology = what psychology researchers say,
because this is the closest we can get to the
“reality” of psychology.
INF 384 C, Spring 2009
Representing competing ideas
But a behaviorist psychologist and a psychologist who
adopts a psychoanalytic perspective may have widely
differing views, even on basic concepts.
Hjorland and Albrechtsen contend that a domain
analysis should uncover these schools of thought that
exist within a discipline, in order to represent them
within an information system.
INF 384 C, Spring 2009
Understanding the significance
of domain analysis
The domain analytic approach acknowledges problems
with the semantic validity of information systems and
asserts the need for systematic and rigorous justification
for knowledge representations.
The domain analytic approach clarifies that a subject
may have many interpretations and provides a means
for validating some of those interpretations.
INF 384 C, Spring 2009
Understanding the limitations
of domain analysis
The domain analytic approach ignores concerns
related to an information system’s audience and
purpose.
The domain analytic approach doesn’t explain
how a designer of subject languages should
decide between competing approaches to the
subject.
INF 384 C, Spring 2009
Performing a domain analysis
Find documents that help you determine ontology
(important things), epistemology (important problems,
theories, methods and practices), and social structures in
the selected domain.
For example:
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–
–
–
–
FAQs, beginners’ guides, and textbooks.
Bibliographies.
Professional organizations.
Online user forums.
Actual people!
INF 384 C, Spring 2009
Using a domain analysis to make
decisions
A domain analysis can help you determine:
• Which sources of information are more
important or representative than others.
• Which concepts to include in a subject
language.
• How those concepts might be defined, labeled,
and related to other concepts.
INF 384 C, Spring 2009
Understanding your responsibility
as a classificationist
A domain analysis won’t actually make decisions for
you; it will just provide information for you to use, in
concert with your audience description, classification
purpose, and your own goals and editorial judgment.
Every classification is a type of argument for a
particular interpretation of a subject. You need to own
that!
INF 384 C, Spring 2009
Types of classificatory structures
Kwasnik identifies three types of structures:
• Hierarchies.
• Trees.
• Facets.
INF 384 C, Spring 2009
Hierarchies
A hierarchy groups concepts from most general
to most specific: each branch inherits
characteristics from its parents.
Dogs exhibit all of the characteristics of
mammals (and thus all characteritics of primates,
and of vertebrates) plus additional
characteristics.
INF 384 C, Spring 2009
Trees
According to Kwasnik, a tree is a looser form
that shows a consistent principle of organization,
but does not have the strict rules of inheritance
and so forth that hierarchies have.
Example:
Grandparents
Parents
Children
INF 384 C, Spring 2009
Facets
Facets are fundamental, ideally orthogonal, categories
of concepts.
Concepts from different facets can be combined to form
more complex concepts without needing to enumerate
all possible combinations in advance.
Example: By keeping processes and materials separate,
we can describe roasting, braising, or frying any kind of
food item, without enumerating each type of food for
every process.
INF 384 C, Spring 2009
Example facets
From Aitchison, possible facets:
• Abstract entities.
• Attributes.
• Materials (constituent substances).
•
Naturally occurring entities.
•
Living entities/organisms.
•
Artifacts (man-made).
•
•
•
•
•
Parts/components.
Agents/actors.
Equipment/apparatus.
Patients (recipients of actions).
Products (of actions).
INF 384 C, Spring 2009
•
Processes (intransitive actions).
•
•
•
Operations (transitive actions).
Place.
Time.
Arrangement within hierarchies
Two forms:
• Showing multiple principles of division that
relate children to their parent node (subfacets).
• Ordering via appropriate principles at each
array (Ranganathan’s canons and such).
INF 384 C, Spring 2009
Showing principles of division
(subfacets)
shoes
high heels
hiking boots
mary-janes
pumps
running shoes
sandals
slingbacks
stilettos
wedges
winter boots
INF 384 C, Spring 2009
shoes
(by season)
winter
spring
(by function)
hiking
running
(by style)
boots
pumps
sandals
(by feature)
slingbacks
mary-janes
(by heel type)
stilettos
wedges
(by heel height)
high heels
Ordering concepts at each level
An “array” is a group of siblings (descriptors at the
same level of hierarchy). These need to be ordered, even
if you don’t need subfacets! Possible orders:
• General to specific.
• Chronological.
• Close to far away.
• Order of a process.
INF 384 C, Spring 2009
Example: music tempos
Allegro
Andante
Largo
Moderato
Presto
Vivace
Largo
Andante
Moderato
Allegro
Vivace
Presto
(alphabetical)
(slowest to fastest)
INF 384 C, Spring 2009
Your mission
• Continue doing research to define the subject.
• Continue compiling a list of potential concepts
to include in your classification.
• For each potential concept, why should it be
there? What is your basis for making this
decision?
• Start thinking about how your concepts might
be structured.
INF 384 C, Spring 2009