Information Organization LBSC 670 Information Organization

Today Case Study in Taxonomies – MESH Explore ontology creation Get started with Protégé

Class feedback “I want to know more about classification, taxonomies, etc . . .” “What ILS does HathiTrust Use?, What is a ‘next-gen’ catalog?” “How much about classification do I need to know?” INLS 520 – Fall 2007 Erik Mitchell

Amazon Xray http://www.youtube.com/watch?v=AbzOLua2baw On the fly indexing

Knowledge Organization “tools that present the organized interpretation of knowledge structures” (Hjørland) “classification schemes that organize materials at a general level…, subject headings that provide more detailed access, and authority files that control variant versions of key information” (Hodge)

A+ A good CV. . . Removes ambiguity Defines relationships between things Contextualizes information A+ Removes ambiguity Synonyms, Homonyms, polysemes, Defines relationships Equivalence, hierarchical, associative (BT, NT, RT, CR) reciprocity, Provides context Category, scope, qualifiers, modifiers, scope notes

Case study - MeSH http://www.nlm.nih.gov/bsd/disted/video/

When is a CV an Ontology? “The study of being or existence” “A conceptualization of a specification” (Gruber) “An ontology formally defines a common set of terms that are used to describe and represent a domain.” (OWL) Computational application of “Necessary and Sufficient” definitions

OWL? Web Ontology Language W3c: “semantic markup language for publishing. . .ontologies on the www” A built-in language: Class subClassOf disjointWith Encoded in RDF or XML

OWL schema INLS 520 – Fall 2007 Erik Mitchell Subject Domain Range: hasSpiciness, hasTopping, hasBase Relationships, Equivalent, Superclass Class / Sub-class: Pizza >> CheesyPizza Instances: A Dominoes Cheese Pizza Class/SubClass: A group of individuals that exist together (e.g. pizzaTopping) and cheeseTopping Instances: Example objects (e.g. a real pizza!) Range: The property limits of a class of objects, typed relationships (hasSpiciness) Relationships / Properties: Equivalence,, Sufficient and Necessary attributes (what can be a cheese pizza vs. what IS a cheese pizza) Equivalent, superclass Domain: Governs inheritance – how the classes/subclases, properties, and ranges fit together The beauty of ontologies is 1) you must be very specific with how you define things. It is not enough to say something IS something, you must also say what it is NOT and 2) Ontologies add power to your taxonomy. - We can easily discover all vegetarian pizzas without re-classifying! INLS 520 – Fall 2007 Erik Mitchell

OWL in Protege Classes Individuals Properties Sets that contain individuals – Taxonomic, superclass/subclass Individuals Examples of a defined concept Properties Binary relationship (hasBase,hasTopping) between individuals Similar to Slots in Protégé 3.4

DC as OWL Classes: DC Document Model Object properties: relationships Data properties: DC elements Individuals: Actual DC records

Assignment 3 - Ontologies Group or individual Focused on skill development Complete tutorial: Ch 1-6 (P1-88) Reflective statement – Migration of LCSH into OWL form Making a change in Assignment 3 Functionally the same Less creative focused but more process focused What you will get out of this is an in-depth understanding of ontology elements Some challenges – This tutorial is not 100% in sync with the current version of protégé. Some differences : Classify = Reasoner, Open inferred hierarchy Window >> class views >> class hierarchy (inferred) Grading: An A – You make it through CH6 and your ontology is largely similar to the tutorial (e.g no errors) A B+ – You make it through CH 4 (p75) and things work