# A Framework for the Evaluation of the Cultural Heritage Information Ontology
## 4 Discussion and Conclusions  
The CIDOC CRM is a hybrid ontology (between foundational and domain) mainly focused on museological concepts such as paintings, archaeological literature, cultural phenomena cultural manifestations, and built heritage. It is not committed to reusing well-known core ontologies, e.g., for locations, time, persons. Our first recommendation for the CIDOC CRM is to reuse the high-level semantics (concepts) from existing and commonly used foundational ontologies. This would shift the CIDOC CRM's generalization level towards the core level and better prepare it for sharing instances of the ontology. The following existing core ontologies semantically intersects with the CIDOC CRM:  
* OWL-Time Ontology, because the _crm:E2_Temporal_Entity_ is the same as _time:TemporalEntity_ ([[https://www.w3.org/2006/time#TemporalEntity](https://www.w3.org/2006/time#TemporalEntity)]([https://www.w3.org/2006/time#TemporalEntity](https://www.w3.org/2006/time#TemporalEntity))). To support this, the largest repository with 681 biomedical ontologies ([[https://bioportal.bioontology.org](https://bioportal.bioontology.org)]([https://bioportal.bioontology.org](https://bioportal.bioontology.org)), accessed on 10 January 2022) shows that, out of 17 ontologies that define the concept TemporalEntity, 14 reuse the concept _time:TemporalEntity_. * Location Core Vocabulary, because the _crm:E53_Place_, which is not complete and clear (see section Ontology Pitfalls), could be the same as loclocation from the Location Core Vocabulary, which actually fully reuses _dcterms:Location_ ([[http://purl.org/dc/terms/Location](http://purl.org/dc/terms/Location)]([http://purl.org/dc/terms/Location](http://purl.org/dc/terms/Location))). To support this, the Bioportal ontologies show that, out of 61 ontologies that define the concept Location, 8 reuse the concept _dcterms:Location_. The Basic Geo (WGS84 lat/long) vocabulary would complement Location Core Vocabulary with GPS positions (latitude and longitude). * Person Core Vocabulary, because _crm:E21_Person_ (comprises real persons who live or are assumed to have lived) is the same as _person:Person_ ([[http://www.w3.org/ns/person](http://www.w3.org/ns/person)]([http://www.w3.org/ns/person](http://www.w3.org/ns/person))) from the Person Core Vocabulary, which is actually a subclass of _foaf:Person_ and _schema:Person_ with the restriction that it only covers an individual person who may be dead or alive, but not imaginary. * SKOS (Simple Knowledge Organization System Reference) provides several properties that map concepts between different concept schemes, and it could link the similar concepts from the CIDOC CRM to other similar ontologies in the Semantic Web (_skos:broadMatch_,  
Figure 2: Quality of the CIDOC CRM according to the improved evaluation with application of new metrics for interoperability. _skaos:narrowMatch_, _skos:relatedMatch_, _skos:exactMatch_ and _skos:closeMatch_), e.g., _crm:E21_Person_ _skos:exactMatch person:Person_. * Schema.org can be used to semantically enrich the concepts _crm:E67_Birth_ and _crm:E69_Death_ with the properties _schema:birthDate_ and _schema:deathDate_. Another example is to link the concepts _schema:CreativeWork_ and _crm:E65_Creation_. The proposed modifications to the cloned CIDOC CRM ontology would increase the score for the interoperability characteristic if combined with a high value for Composability (_CPOnto_) while maintaining a low value for the Aggregability (_AGOnto_). Building on the notion that information not shared is information lost, the new proposed metrics Extremes (_EXOnto_), Composability (_CPOnto_), and Aggregability (_AGOnto_) stimulate interoperability and guarantee completeness and sustainable ontology maintenance.