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: 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). Processes (intransitive actions). Operations (transitive actions). Place. Time. INF 384 C, Spring 2009

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 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 INF 384 C, Spring 2009

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 (alphabetical) Largo Andante Moderato Allegro Vivace Presto (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