# A Framework for the Evaluation of the Cultural Heritage Information Ontology
## 2 Related Work
### Core Ontologies for Reuse  
Reusing existing ontologies when building a new one is still a practice not established in some domains [36]. Taking already-existing knowledge when creating new ontologies is particularly advantageous when core ontologies are reused. This step needs to be included and analyzed when ontology engineering processes are being implemented. One of the first advantages is the elimination of duplicated components, being sufficient to reference them as already existent in the reused external core ontologies. According to [37], ontologies are categorized as foundational, core domain, and domain ontologies. Foundational ontologies (FO), also called top-level, reference, high-, upper-, or meta-level ontologies, are domain independent and contain basic and general concepts and relations that can be reused in many arbitrary domains. Basic concept in FOs can be a fundamental higher level philosophical abstraction, e.g., \"endurants\" or persistent objects such as a person or castle in UFO-A [38], e.g., \"perdurants\" or temporal events such as a medieval period or reconstruction works in UFO-B, or simpler, lower-level daily business terms, e.g., \"Obligation\" in FO gist [39]. When the higher- and lower-level approach is combined within a single ontology, this is regarded as hybrid ontology. The reuse of basic, fundamental, and well-established concepts prevents the duplication of underlying concepts, already well defined by specialized communities and organizations. The result of standardization processes and agreements, these concepts are stable, and their usability and applicability are guaranteed. Several concepts can therefore be identified as core for the heritage buildings domain. Several core ontologies were identified and considered relevant for reuse:
* The Dublin Core Metadata Element Set establishes a vocabulary for cross-domain resource description [40]. The set includes 15 terms: contributor, coverage, creator, date, description, format, identifier, language, publisher, relation, rights, source, subject, title, and type. The ISO 15836-2:2019 describes classes and properties of these metadata terms. * Temporal concepts are part of the time ontology in OWL [41]. Including 19 classes (_time:DateTimeDescription_, _time:DateTimeInterval_, _time:DayOfWeek_, _time:Duration_, _time:Interval_, etc.) and 58 properties (e.g., _time:after_, _time:before_, _time:hasDuration_, _time:weeks_), the ontology can be reused for the description of the temporal properties of heritage buildings resources. * For the description of people, the connections between them, and what they create and do, the Friend of a Friend (FOAF) Vocabulary Specification [42] establishes concepts such as (_foaf:name_, _foaf:familyName_, etc. ), linking a specific person, as an engineer or an architect, to information about the building; for example, through properties as _foaf:title_ and _fa:currentProject_. * The ISA Programme Location Core Vocabulary [43] is used for concepts describing a place in terms of three classes: location, address, and geometry, combined with properties such as full address, post code, etc. * Basic Geo (WGS84 lat/long) vocabulary [44] complements the ISA Programme Location Core Vocabulary for exact geometry (lat/long), e.g., wgs84_posfPoint is composed of wgs84_pos:lat and wgs84_pos:lon. * The ISA Programme Person Core Vocabulary [45] can be reused due to the simplified description of a person, using three classes: person, code, and identifier, and properties such as family name, patronymic name, gender, birthdate, place of birth, country of birth, citizenship, residency, etc. * The Simple Knowledge Organization System Reference (SKOS) [46] serves for semantically linking concepts between different web-based knowledge organization systems related to heritage buildings, e.g., _skos:closeMatch_, _skos:exactMatch_, _skos:prefLabel_.