CIDOC CRM compatibility is determined on the basis of the formal-logical compatibility of an ontology with CIDOC CRM. The ontology in question may be the result of academic research, of specific communities of practice or applied schemata of specific projects for the representation of cultural-historical or history of science data.
These models may serve as potential solutions for other applied projects or elicit further development by other teams or wider communities or as a pool of modelling ideas and best practices that can be shared in a decentralized manner across the community. They are welcomed in addition to the present scope and resources for ontology development by the CRM SIG, manifested in its present base ontology and harmonized extensions, which are guided by the goal of making standards with long-term validity for information integration under precisely defined, standardized high-level concepts. Such experience can then, in principle, feed back to the CIDOC CRM SIG for its immediate maintenance and development processes.
The basic certification procedure will define an attribute of formal-logical compatibility, including a “shallow” assessment of the semantics of the submitted model. It is however expected (1) that the model has been developed for an explicit functionality of use; (2) that it constitutes an actual result of empirical analysis of an - at least in samples - accessible body of data (3) that its development has been informed by the CRM Principles document. Note, that the certification procedure will obviously not ensure ontological consistency or ambiguity between the extended parts of different CRM compatible ontologies [i.e.: will not harmonize the ontology]. The latter is the task of “harmonization”.
CIDOC CRM compatible ontologies may be contributed for listing on the CIDOC CRM website under the following principles.
- Ontological Consistency
- Open Source
- External Responsibility
- Full Documentation
- Invitation to on-going integration efforts
Consistency (read more)
The submitted model should be aligned to the CIDOC CRM through sub and super class and property statements, joining the ontological model proposed to the overall logic and structure of the CIDOC CRM base ontology and officially approved harmonized extensions, as defined in the section “Extensions of CIDOC CRM” of the Definition of the CIDOC CRM. In this regard,
- the sub- and super- class and property declarations must be logically compatible with the inferences of the CIDOC CRM data model, including quantifiers.
- The scope notes should ontologically be compatible with the definitions of the related CIDOC CRM classes and properties.
- New classes and properties must not cause ambiguity of instantiation with existing CRM classes. I.e., it must be decidable if an item is an instance of a new or a class of the CRM or of an official version of a harmonized extension, or instance of both.
- They should further respect the basic disjunctions in the ontology, which are temporal events vs persistent items, conceptual objects versus physical objects, place, time and spacetime.
The logical consistency of IsA relations should be checked automatically using some ontology reasoner tools, best by the submitter. Conditions 2-4 constitute a shall semantic check that will be assessed by assigned CIDOC CRM SIG reviewers.
The formal semantics should be compatible with that of the CIDOC CRM as defined in: Meghini, C. and Doerr, M. (2018) ‘A first-order logic expression of the CIDOC conceptual reference model’, International Journal of Metadata, Semantics and Ontologies, 13(2), pp. 131–149. doi: 10.1504/IJMSO.2018.098393.
Open Source (read more)
CIDOC CRM SIG is an organization responsible for the development and maintenance of ontology standards for cultural heritage data and as such it is committed to the open source sharing and reuse of its ontological models and their potential extensions. As such, any extension proposed for listing as a compatible extension on the official website by default should be an open source document reusable by the public towards the generation of semantic data.
Therefore, every proposed extension must be accompanied by a valid open source copyright claim, such as CC BY 4.0 or a practically equivalent license.
External Responsibility (read more)
The CIDOC CRM SIG claims no responsibility for the models submitted with regards to their maintenance or longevity. Submitters of extensions take full responsibility for the maintenance and hosting of their extensions and may offer user support. Potential users of these models should consult the documentation of the model to understand the commitment of the maintainer of that model, with regards to the long-term reusability and compatibility of that model.
This externality of responsibility will be noted on the CIDOC CRM site where Compatible Models are listed. Moreover, submitters of models are expected to have a description of their maintenance policy on the site where they host their ontology.
Full Documentation (read more)
The functionality of CIDOC CRM as a formal ontology for cultural heritage relies on the CRM SIG’s development of a rigorous documentation methodology for creating and maintaining a well-defined and transparent ontology that is first and foremost a specification document which is also elaborated as various serializations. Submitted extensions should follow the CIDOC CRM style specification document for the definition of the extensions scope, its classes and properties, at least in its functional structure of sections. The specification should be populated with examples for classes and properties.
Graphics should present functional units of related classes and properties, and a complete graphical IsA hierarchy of its classes should be provided.
A graphical instantiation example is also expected
N.b.: In case the submitted documentation is elliptical or does not meet the SIG’s standards, the SIG can always request that the documentation at hand be redrafted.
Invitation On-Going Integration Efforts (read more)
Submitters of CRM Compatible Models are assumed to wish to have reference to their work as part of an on-going community process to develop integrated, harmonized standards for semantic data construction. Submitters of models are invited to be or become members of the SIG and participate as possible in the life of the community, but particularly in discussions regarding the development of harmonized extensions of CIDOC CRM that may provide integrated, long term CIDOC CRM approved extensions for constructs that may fall within the scope of the models they have contributed.
Submission procedure
Candidate ontology is proposed to the SIG through the following procedure:
- Proposer fills out form with requisite metadata for the ontology
- Proposer officially requests listing the Ontology under “CIDOC CRM Compatible Ontologies” subsite.
- Proposed ontology is checked that it matches requirement for requested status
- Two SIG members assigned to review
- Report given at next SIG
- Vote taken
- If approved, ontology listed (in relevant section)