EMMO: an Ontology for Applied Sciences
What are Ontologies?
An ontology is a formal description defining the organization of knowledge, intended as a set of concepts within a domain together with the relationships that hold between them  . To enable such a description, we need to formally specify components such as individuals (instances of objects), classes, attributes and relations, as well as restrictions, rules and axioms. An ontology therefore effectively defines a common vocabulary for researchers who need to share information within a certain domain. As a result, ontologies do not only introduce a sharable and reusable knowledge representation of the domain, but can also add new knowledge about the domain itself.
Spectrum of Semantic Knowledge Organisation
There are, of course, other methods that use formal specifications for knowledge representation such as vocabularies, taxonomies, thesauri, topic maps and logical models, as represented in the graphics below. However, unlike taxonomies or relational database schemas, for example, ontologies offer the significant advantage of providing a way to express relationships, thus enabling users to link multiple concepts between each other in a variety of flexible ways.
The European Materials Modelling Ontology (EMMO)
The European Materials Modelling Ontology (EMMO) is the result of a multidisciplinary effort within the EMMC, aimed at the development of a standard representational ontology framework based on current materials modelling and characterization knowledge. Instead of starting from general upper level concepts, as done by other ontologies, the EMMO development started from the very bottom level, using the actual picture of the physical world coming from applied sciences, and in particular from physics and material sciences.
The EMMO has grown from the bottom (i.e. scientific application field) to the top (i.e. conceptualization), staying focused on the original scope while at the same time maintaining an approach as general as possible. The ontological framework has been built around concepts like elementary particles, wave-particle dualism, finiteness of space and time intervals coming from the perspective for experimental physics. The development of the mid and upper layers of the ontology has been functional to the respect of these low level concepts, to facilitate the understanding of the high level concepts to users with limited or no philosophical background.
A summary conceptual visualization of the main EMMO operations and objectives is illustrated in the figure shown below:
The form of knowledge generated by this approach has been formally expressed using methods of analytical philosophy (e.g. mereotopology) and by means of languages and technologies made available by ICT experts (e.g. OWL), in a strong multidisciplinary approach. In this sense the EMMO is more an ontology for applications than an applied ontology.
Generally-speaking, EMMO has the objective of becoming a practical tool to achieve interoperability in the areas of describing, processing, characterizing and modelling of materials and of their properties. Once being established in an electronically readable form, such an ontology, together with its extensions, also provide formal categorization schemes to complement machine learning, to facilitate digitalization of industrial materials technologies, and to help with the integration of artificial intelligence (AI) and Big Data approaches.
Additional Information on EMMO
The remainder of the present webpage provides further introductory content to the foundational concepts of the EMMO ontology. We also recommend to review the use of the Taxonda Registry , a standard documentation of semantic assets operated by the EMMC.
EMMO Videos and Presentations
Video recordings of seminars and presentations on EMMO-related concepts can be found in the videos linked in what follows. Additional introductory material and copies of presentation slides on this topic can be retrieved within the shared folder accessible via the link in Ref. .
Introduction to Ontology and Interoperability by Alexandra Simperler
EMMO Seminar by Emanuele Ghedini
A new international Task Group on Materials Ontologies was launched at the Research Data Alliance (RDA) 13th Plenary Meeting in Philadelphia on 4th April 2019. It recognises the growing importance of ontologies in the Materials Science domain, for delivering on the objectives and opportunities connected with digitalisation and the “Materials 4.0” agenda, in particular interoperability, information transparency, decision support based on data plus models, and artificial intelligence.
Additional information on the efforts by the RDA to contribute to the development of Materials Ontologies can be found under the link in Ref. .
The Industrial Ontologies Foundry (IOF) is a group working to co-create a set of open ontologies to support the manufacturing and engineering industry needs, and to advance data interoperability.
Their website  contains information on IOF activities and industrial ontology events and developments, as well as educational resources for industry users and ontology developers.
EMMO is developed and distributed with a Creative Commons licence via a GitHub repository . Please complete the contact form for any queries.
In addition to the ontology itself, the repository contains also a Python API for EMMO. It is based on Owlready2 , a module for ontology-oriented programming in Python 3.