ArtSTOR

When the RubberHits the Road Using the CIDOC CRMin the Real World

Tony Gill

27 March 2003

ArtSTOR

Outline

The problem of cultural information diversity

Data models and ontologies

CIDOC CRM overview

Mapping to the CIDOC CRM

CRM benefits

Real-world & envisioned applications– RLG Cultural Materials

The future?

ArtSTOR

Cultural infodiversity

Cultural information held by museums, libraries and archives is necessarily heterogeneous

– Curatorial approaches

– Subject disciplines

– Granularity

– Level of detail

– Data structure

– Data content values

ArtSTOR

Cultural infodiversity

Cultural information held by museums, libraries and archives is necessarily heterogeneous

– Curatorial approaches

– Subject disciplines

– Granularity

– Level of detail

– Data structure

– Data content values

Infodiversity is good!

ArtSTOR

Example 1: Photograph

Type: ImageTitle: Allied Leaders at Yalta Date: 1945Publisher: United Press International (UPI)Source: The Bettmann ArchiveCopyright: CorbisKeywords: Churchill, Roosevelt, Stalin

ArtSTOR

Example 2: Document

Type: TextTitle: Protocol of Proceedings of Crimea Conference Title.Subtitle: II. Declaration of Liberated Europe Date: February 11, 1945.Creator: Premier of the Union of Soviet Socialist Republics Prime Minister of the United Kingdom President of the United States of AmericaPublisher: State Department

“The following declaration has been approved:The Premier of the Union of Soviet Socialist Republics, the Prime Minister of the United Kingdom and the President of the United States of America have consulted with each other in the common interests of the people of their countries and those of liberated Europe. They jointly declare their mutual agreement to concert… and to ensure that Germany will never again be able to disturb the peace of the world…”

ArtSTOR

Example 3: Getty TGN record

TGN ID: 7012124Names: Yalta (C,V), Jalta (C,V) Types: inhabited place(C), city (C)Position: Lat: 44 30 N, Long: 034 10 EHierarchy: Europe (continent) <– Ukrayina (nation) <– Krym

(autonomous republic)Note: …Site of conference between Allied

powers in WWII in 1945…Source: TGN, Thesaurus of Geographic Names

ArtSTOR

Example problem

Heterogeneous descriptions clearly linked by a common event

Only matching data value is “1945”!

ArtSTOR

Cultural infodiversity

No single (meta)data schema fits all

Significant conceptual overlaps– e.g. People, places, events, objects, relationships

Traditional “compromise” approach– Generic simple descriptions for initial discovery

e.g. Dublin Core

– Rich domain-specific descriptions for depthe.g. EAD, MARC

Access by lowest common denominator

Crosswalk proliferation mapping madness!

ArtSTOR

Data models

Data models are structures for information

Good data models “mirror” the reality the data are attempting to describe

Different data modeling methodologies– Entity-Relation (Relational, SQL, RDBMS)

– Object-Oriented (O-O, OODBMS)

– Semantic Networks (RDF, DAML+OIL)

Few cultural information standards are based on good data models!

ArtSTOR

Ontology

“A branch of metaphysics concerned with the nature and relations of being”

– Merriam Webster Collegiate Dictionary

“Ontology” co-opted by knowledge representation & computer science communities

“A specification of a conceptualization”– Tom Gruber, “A translation approach to portable ontologies”

Knowledge Acquisition, 1993

Thesauri & classification schemes are ontologies!

ArtSTOR

CIDOC Conceptual Reference Model

Object-oriented “domain ontology”– Formalizes the semantics required to describe objects and

relationships in the cultural heritage context

– NOT a metadata standard! But can be used to express metadata standards

Represents over a decade of development– Based on ICOM/CIDOC “International Guidelines for Museum

Object Information: The CIDOC Information Categories”

– Scope covers rich information exchange between museums, libraries and archives

ArtSTOR

“The primary role of the CRM is to serve as a basis for mediation of cultural heritage information and thereby

provide the semantic 'glue' needed to transform today's disparate, localised information sources into a coherent

and valuable global resource.”

Martin Doerr & Nick Croftshttp://cidoc.ics.forth.gr/

ArtSTOR

CRM overview

CRM v3.4 comprises 84 Classes interlinked by 139 Properties

Classes inherit properties from their parents, or Superclasses

Event-centric and empirical; observations about the world

Short-cuts, for typically incomplete knowledge

Highly extensible through Sub-typing of classes and properties

Ideally suited to RDF implementation

ArtSTOR

Scope of the CRM

Intended scope: Exchange and integration of scientific documentation about museum collections

– “Scientific” means sufficient depth & precision for research

– “Museum” defined by ICOM

– Includes contextual information

– Includes exchange between museums, libraries & archives

– Excludes administrative information, e.g. visitor statistics

Practical scope: The set of extant data sets and structures used in museum documentation

“The curated knowledge of museums”

participate in

Actors Conceptual Objects

Physical Entities

Temporal Entities

affect

Types

refine

Ap

pe

llati

on

s

ide n

t ify/

na

me

location

occur atwithin

Time-Spans

Places

ArtSTOR

Mapping to the CRM

Mappings entail “deconstruction” of original records– Artifact-centric nature of descriptions discarded

– Implicit entities (especially events) made explicit

Mappings to existing standards– EAD

– IFLA FRBR

– SPECTRUM

– AMICO

– And others

ArtSTOR

Making implicit concepts explicit

The element DC.Creator implies:– An Actor, who created something

– An Actor Appellation by which to identify the creator

– An Event, the act of creation

– Some Man-Made Stuff, the physical or conceptual thing that was created and is being described by the DC record

E24 Physical Man-Made Stuff p108 was produced by E12 Production Event p14 carried out by E39 Actor p131 is identified by E82 Actor Appellation

E28 Conceptual Object p94 was created by E65 Creation Event p14 carried out by E39 Actor p131 is identified by E82 Actor Appellation

E31 Document“Yalta Agreement”

E7 Activity

Crimea Conference

E65 Conc. Creation

*

E52 Time-Span

February 1945

E39 Actor

E52 Time-Span

1945-02-11

E39 Actor

E39 Actor

E53 Place

7012124

E38 Image

carried out

participated in

falls within

took place at

within

within

refers to

has created

ArtSTOR

Benefits of the CRM

Elegant and simple compared to comparable Entity-Relation model

Coherently integrates information at varying degrees of detail

Readily extensible through object-oriented class ‘typing’ and ‘specializations’

Richer semantic content; allows (some) inferences to be made from ‘fuzzy’ data

Designed for semantically lossless mediation of heterogeneous cultural heritage information

ArtSTOR

CRM learning curve

Model necessarily complex in order to model the broad domain of cultural heritage information

Object-oriented modeling paradigm unfamiliar compared to entity-relation modeling

– Just similar enough to be confusing!

– Object-oriented models can be implemented using relational DBMS

Notation problems– Difficult to express mappings textually

ArtSTOR

Real-world applications

Conceptual reference– Disambiguating dialogue (especially between domain & technology

experts)

– Validation of schema (c.f. Patrick LeBouef, FRBR)

Information exchange– Canonical “master” mappings

– Expression in XML or RDFS

ArtSTOR

Real-world applications

System & schema design– RLG Cultural Materials (U.S., more next slide…)

– Finnish National Gallery Database (Finland)

– City of Geneva MusInfo Project (Switzerland)

– Germanische Nationalmuseum Nuremberg (Germany)

– Monument Inventory Data Standard (U.K.)

– Heritage Data Dictionary (U.K.)

– CLIO Cultural Documentation System, ICS-FORTH & Benaki Museum (Greece)

ArtSTOR

RLG Cultural Materials

Online multimedia resource

Cultural content aggregated from diverse international alliance of RLG member institutions

“Where Museums, Libraries & Archives Intersect”

ArtSTOR

RLG Cultural Materials Data Model

Wildly heterogeneous data

Support “who, what, when, where” access

Access paths for searching reviewed by Description Advisory Group

Resulted in “event-based” data model, influenced by:– CIDOC Conceptual Reference Model

– <indecs> Metadata Framework

– ABC/Harmony Logical Model

Specialization by Type

ArtSTOR

Object production information

Man made object

Man made object

Production

ActivityActors

performed (carried out by)

had specific purpose (was purpose of)

had general purpose (was purpose of)

used object (was used for)

produced (was produced by)

was generally used

Type

ArtSTOR

Object production information

Man made object

Man made object

EventActors

performed (carried out by)

had specific purpose (was purpose of)

had general purpose (was purpose of)

used object (was used for)

produced (was produced by)

was generally used

Type

Cultural Materials Logical Data Model

Version: 2001-05-04‘T’ signifies a link to the Type entity (not displayed for clarity)

“Show me photographs of New York from the 1940’s…”

PlaceName = “New York”EventType =

“creation”EventBeginDate = “1940”EventEndDate = “1949”

WorkType = “Photograph”

surrogateURL = “http://…”

ArtSTOR

ArtSTOR

Envisioned applications

Mediation systems & agents– Meaningful queries and results across distributed heterogeneous

data sources

Semantic web for culture?

ArtSTOR

The future

Recognition of the benefits of adherence to cultural descriptive standards

Extension standards for data syntax & values

“Entity Identity” problem

Shared interdisciplinary authority files– E.g. Getty ULAN, LC NAF, Encoded Archival Context Initiative

Semantic web for culture– Gradual transition from record-centric documentation to knowledge

networks

– How to navigate potentially unbounded networks?

– How to maintain links within potentially unbounded networks?