1. Information Organization
LBSC 670
Information Organization

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

3. 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

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

5. 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)

6. 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

7. Case study - MeSH

8. 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

9. 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

10. 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

11. 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

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

13. 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