A couple of frameworks for mapping TLOs Formalization of links Across Top-Level OntologieS (FATLOS) Workshop 21 st April 2022 Chris Partridge Structure The practical (data) problem Coarse grained framework (architecture) – metaphysical choices Fine grained framework – basic ontological patterns 2 The practical (data) problem TLO: A TLO: B TLO: C need to update this picture Sharing data across TLO-based Digital Twins: Raises TLO mapping requirements 3 Two frameworks to help manage the mapping requirement coarse grained framework (architecture) – metaphysical choices fine grained framework – basic ontological patterns 4 coarse grained framework (architecture): metaphysical choices 5 Background: Information Management Framework UK’s National Digital Twin programme (NDTp) Information Management Framework (IMF) “a national system for connecting digital assets designed to enable competition on delivery and encourage innovation and development over time” Policy paper - National Data Strategy - Published 9 September 2020 “The steps we will take to consolidate the framework and approach, working with regulators and the Better Regulation Executive where appropriate, will include the coordination and alignment of existing work to build on data foundations across the economy, such as: working across the physical environment, including the standardisation of data about location, the built and natural environment, and transport and other infrastructures. This will include further developing the Information Management Framework , which will seek to establish a common language by which digital twins can communicate securely and effectively, part of the Centre for Digital Built Britain’s work towards developing a National Digital Twin.” https://www.gov.uk/government/publications/uk-national-data-strategy/national-data-strategy 6 style.visibility style.visibility style.visibility style.visibility style.visibility A framework for assessing an ontology’s architectural choices 7 https://www.repository.cam.ac.uk/handle/1810/313452 Appendix E: Summary of Framework Assessment Matrix Results 31 ontological choices 37 top ontologies shortlisted and assessed The ontological choices shape the architecture of the ontology web-based: https://digitaltwinhub.co.uk/a-survey-of-top-level-ontologies/#a_survey_of_TLOs_contents The choice of whether to stratify or unify 4.2.2 Horizontal aspects: stratification versus unification There is a group of fundamental choices that impact the ontological architecture which involves whether or not to make a distinction. If one chooses not to make the distinction, one only introduces a single type. If one chooses to make the distinction, one introduces two types; one for each alternative. The choice boils down to whether to horizontally stratify or unify. One can describe choosing to make the distinction as ‘separating one potentially unified type into two’, creating a horizontal stratification in the hierarchy – and not making the distinction, ‘unifying the potentially separated two types into one’. Or in BFO’s case, to choose both 8 Seeing this as a ‘Horatio’ (logical) problem Separating or unifying changes the domain of discourse The stratification analysis tells you where these (types of) changes will occur. Name ‘Horatio’ borrowed from: “Any non-trivial ontology involves universal and existential quantification. In other words, the ontology states something about all entities in the intended universe of discourse, and asserts that something exists in the universe of discourse that meets certain conditions. Thus, the meaning of quantifiers like ‘every’ and ‘something’ depends on the intended universe of discourse.” Fabian Neuhaus and Pat Hayes. 2012. Common Logic and the Horatio problem. Appl. Ontol . 7, 2 (April 2012), 211–231. 9 Horizontal Aspects: Stratification: unifying and stratifying 10 Example multiple stratification Figure 12 – An example top-level ontology stratification journey – BFO stages 1 to 3 {5C22544A-7EE6-4342-B048-85BDC9FD1C3A} Label Unified type Separate types Stratifying relation spacetime spatio-temporal objects spatial objects, temporal objects spaces are multiply located at times (though this is often a derived relation – from an occupying object’s links to both space and time) locations supersubstantival objects (physical) objects, locations objects are (exactly) located at their locations properties objects substances, properties substances are bearers of properties endurants perdurants continuants, occurrents occurrent is dependent upon continuant immaterial (physical) objects material objects, immaterial objects immaterial objects are part of material objects Table 8 – Summary of the horizontal stratification choices introduced 11 Spacetime stratification: unifying or stratifying A key choice: unifying or stratifying space and time temporal entities spatial entities e ntities more stratified supersubstantival objects more unified happens at {5C22544A-7EE6-4342-B048-85BDC9FD1C3A} location 1D time plus 3D space 4D spacetime instant (in time) a (simple) point on the 1D timeline. a (complex) horizontal slice in spacetime a point of space a (simple) point in 3D space a (complex) vertical line in spacetime a spacetime point A point in 3D space located at a point in 1D time. a (simple) point in 4D space 12 spacetime time more unified space more stratified BFO DOLCE ProtOn Spacetime stratification: examples 13 fine grained framework basic ontological patterns 14 Background Writing the CLIF for the IMF’s TLO Adopting programming approach to developing agile code in particular, Clean coding Found it useful to regiment finer grained (low level) ontological patterns into the CLIF code. Many benefits, including simplified migrating to other notations; for example, OWL and UML No evidence as yet, but suspect this will make lower level mapping between different TLOs easier. 15 Micro ontology pattern: subsumption Subsumption: a relation where the extension of one type is a subset of the extension of the other Two issues If explicit, multiple ways to express logically May be implicit – inferable from other formulae Strategy: require these relations to be made explicit Simple version: adopt a convention to write these explicitly, even if they can be inferred from other formulae write these in a preferred format An alternate strategy would be to calculate all the subsumptions: See: Hahmann , T., Powell II, R.W. (2021). Automatically Extracting OWL Versions of FOL Ontologies. https://doi.org/10.1007/978-3-030-88361-4_15 16 Subsumption – Format and Example Preferred format: Example: 17