Il ruolo delle “ core ontologies ” nel ciclo di vita del prodotto culturale digitale

1. Il ruolo delle “core ontologies”nel ciclo di vita del prodotto culturale digitale Il caso “CIDOC-CRM” Oleg Missikoff - Prima giornata di studi sul SW Culturale – Roma, 6 luglio 2004

2. Life-cycle of a digital/virtual cultural resource Identification Acquisition Description Binding Access Feedback • Policies • Stategies • Marketing • Feedback analysis Digitisation Purchase Creation Info atoms • Metadata • Ontologies • Semantic annotations • User- profiling • Story- telling • Info obj. • Portal technology • Software agents • eLearning modules • On-line questionn. • Polls • Forums • Interviews • Mailing list

3. IDEA MetaLevel Activity Entity ( modeling ideas : Action Location ISA metatypes ) Relation Object instantiation Museum Vase Intensional Level ISA ( conceptual model : Krater Archive types ) instantiation ... Metropolitan Extensional Level ( factual model : Vaso François objects ) The Three Levels of Knowledge Class Language Event Time Attribute Excavation Cratere di Vix Louvre Archivio di Stato

4. The Conceptual Layers Top-down? CIDOC CRM Upper Domain Ontology Specialization Core Ontology Middle-out! Aggregation Lower Domain Ontology The Ontology “Chestnut” Or Bottom-up?

5. The CIDOC CRM • The CIDOC CRM is a Conceptual Reference Model proposed by the Comité International pour la DOCumentation of the International Council of Museums • It is an object–oriented domain ontology for the interchange of rich and heterogeneous cultural heritage information from museums, libraries and archives • Its purpose is to provide a building block for supporting the development of a global Semantic Cultural Web • It is maintained by the CIDOC CRM Special Interest Group, a diverse international group of museum information professionals with an official mandate from ICOM/CIDOC to develop and promote the standard.

6. The CIDOC CRM (2) • Work on the CIDOC CRM formally began in 1996, although it is the evolutionary descendent of CIDOC data standards initiatives going back to 1980 • The primary function of the CIDOC CRM Special Interest Group (CIDOC CRM–SIG) over the last five years has been to test and refine the CIDOC CRM in preparation for publication by ISO, the International Organization for Standardization • The CIDOC CRM was accepted by ISO as "Committee Draft" ISO/CD 21127, and its publication as a full International Standard is due late in 2004.

7. The CIDOC CRM (3) • The CIDOC CRM is comprised of a class hierarchy of 81 named classes, interlinked by 132 named properties • Because it follows object oriented design principles, the classes in the hierarchy inherit properties from their parents, also known as superclasses • From the various terminologies in use for object-oriented models, for ease of understanding by non-computer experts, the following have been selected : • “Entity” for anything that may be called “class”, “entity” or “node”. • “Link” for anything that may be called “attribute”, “reference”, “link”, or “property”. • “Superclass - Subclass” relations refer to “isA” relations, “subclass – superclass”, “ parent class - derived class”, “generalization - specialization”, etc.

8. refer to / refine affect or / refer to participate in location E52 Time-Spans E53 Places Top-level Entities relevant for Integration E55 Types E41 Appellations E28 Conceptual Objects refer to / identifie E39 Actors E18 Physical Stuff E2 Temporal Entities at within

9. A typical problem: chronology mgmt • Information should be positioned in the appropriate time-space context • Dates are often vaguely expressed: • Beginning of ‘800 • First half of XIX century • Between 1825 and 1830 • Circa 1827 • ...

10. The CIDOC CRM and Time P81 ongoing throughout Duration (P83,P84) before after “intensity” Event time P82 at some time within

11. The CIDOC CRM and Time (2) • P81:Time-Span E52 at least covering Time Primitive E61 • P82:Time-Span E52 at most within Time Primitive E61 • P83:Time-Span E52 had at least duration Dimension E54 • P84:Time-Span E52 had at most duration Dimension E54

12. E61 Time Primitive Belongs to: Value Type Subclass of: Primitive Value Scope Note: This entity is a primitive value that should implement appropriate validation and interval logic for date ranges and precision relevant to cultural documentation. The entity is referenced by: Time-Span: at most within Time-Span: at least covering

13. E52 Time-Span Belongs to: Time Type Subclass of: CRM Entity Scope note: A determination of a range of dates or duration without any further connotations to be used to confine periods, events, and any other phenomena valid for a certain time. A time appellation is a verbal form which refers to a time-span. The time-span itself is a temporal extent in the sense of Galilean physics. Different time-appellations may express the same time-span. Examples: from 12-17-1993 to 12-8-1996, 14h30 – 16h22 4th July 1945, 9.30 am 1.1.1999 to 2.OO pm 1.1.1999, Duration of the Ming Dynasty.

14. E54 Dimension Belongs to: Measure Type Subclass of: CRM Entity Scope note: This entity is an abstract class for properties that are measured by some calibrated means and result in numerical values. Dimensions should be recorded according to ISO standards, or using internationally recognized non SI units whenever possible (ISO 31:1992, Quantities and units; ISO 1000:1992, SI units and recommendations for the use of their multiples and of certain other units). Examples: currency: £26.00, length: 4 cm, diameter: 26 mm, weight: 150 lbs, density: 0.85 gm/cc, luminescence: 56 ISO lumens, tin content: 0.46 %, "taille au garrot": 5 hands, C14 date: 2460 years, etc.

15. Conclusions The “core ontology” approach could provide support in the construction of new applications. In fact, usually, domain experts lack specific skills. For this reason, having an Upper Domain Ontology and as many Lower Domain Ontologies as possible could enable an “economy of scale”. It will result in a reduction of human work and, meanwhile, very useful guidelines.

16. Ontology building process Knowledge engineers Domain experts Contents representation Discussion and agreement about contents supported by a groupware environment (HarmoConsys) SymOntoX Domain Ontology

17. Grazie per la vostra attenzione!