Ontology, ontologies and ontological reasoning 2: what do ontologies represent?

1. Ontology, ontologies and ontological reasoning2: what do ontologies represent? Joost Breuker Leibniz Center for Law University of Amsterdam

2. Overview • Reference to `conceptualizations’ • Knowledge and semantics • Kinds of conceptualizations • Representing/expressing conceptualizations • LKIF-Core • Towards a top ontology based on common sense • A cognitive science perspective • Main categories explained

3. Conceptualizations and representations • “…ontology the specification of a conceptualization…” • Confusion about what ontologies are vs what they represent • They are representations, i.e. expressions in some medium. • They represent conceptualizations of terms used in a domain • Barry Smith’s (2008) illustrates the confusion…

4. Cognitive representations Representational artifacts Reality

5. Ontologies are here

6. Ontologies are here? But where is the conceptualization?

7. or here

8. or here? But is this the conceptualization of a term or of an image??

9. Ontologies do not represent concepts in people’s heads

10. Ontologies do not represent concepts in people’s heads…but not this way…

11. Like the scientific theories from which they derive, they represent universals in realitye.g. leg

12. Like the scientific theories from which they derive, they represent universals in realitye.g. leg

13. Cleaning up? • The `scientific’ theories are conceptualizations • The leg is an instance of leg • There are `scientific’ (eg in anatomy) and common sense legs (eg `nice legs’), … • Where’s HERE the ontology? • Extra misleading due to using 2`analog’ representations: • Screen • Drawing (via some `conceptualization’: perception) • An ontology is a symbolic representation of concept (eg leg) • This representation should capture the meaning…

14. Having this clarified, there remain new ambiguities • What kind of conceptualizations do ontologies capture? • How we directly understand and communicate the world (common sense), or • Models of worlds derived from controlled observation (`scientific’) • (Models from speculation (eg meta-physics)) • Ontologies represent: • (Parts of) knowledge (bases, specifications) (AI) • Repositories of semantics (Semantic Web, Computational linguistics)

15. Semantics and knowledge • What we know about terms vs what terms mean in a particular context (domain, document, phrase,..) • Semantics is the result of applying knowledge to data: • It gives meaning to data (signs)  information • In the process of understanding, those `properties’ of terms are selected that make up a coherent `macro-structure’ (model). • It is contextualized knowledge

16. spatial representational system propositional representational system kinesthetic and other representational systems knowledge and semantics (cf Levelt, “Speaking”, CUP 1993, fig 3.1) semantics (meaning/sense) semantic representations (preverbal messages) FORMULATOR ontologies? knowledge

17. sense vs meaning what is this? this is a car • in traffic: a car is a vehicle, moves, transports,… • for the mechanic: a car is a device, has a motor, etc • for a car salesman: a car is a commodity, has a price, a colour, accessories,… • for an insurance inspector: “is this a car or a wreck?”

18. transport level of abstraction vehicle car taxi context dependency context dependency of meaning • the more abstract, the less properties, and the less possible variation in meaning/sense • context dependency: views select properties

19. transport level of abstraction vehicle car taxi context dependency levels of ontologies • top, upper, foundational ontologies • the `primitives’ on which we build our knowledge (eg space, time, object, process, substance, etc.) • core ontologies: • some field of practice, discipline (e.g. medicine, law, etc.) • domain ontologies: • the domain of interest, e.g. (Dutch) traffic law,

20. The more abstract, the more meaning overlaps with conceptual knowledge • Domain ontologies are usually capturing `semantics’: this limits reuse • Lingua Universalis view: • Words < -- > Concepts • Now: • Words < -- > Meaning < -- > Concepts < -- > Knowledge | Context

21. What kind of conceptualization? • Domain ontologies consist usually of a specialized terminology and a particular view on some world. • Core ontologies mediate between some `top’ ontology and the main concepts in a domain • Eg: medicin  scientific notions about biological processes • Eg: law  refined terms to interpret `common sense’ events (sense) • Current top ontologies do not take common sense seriously, neither do they commit to `real’ scientific concepts • For example: space & time

22. Space in top ontologies: a `scientific’ perspective • SUMO, DOLCE, CyC, BFO, etc • 3 dimensions: 3D ontology for objects (continuants) • Time added:4D ontology for processes (occurrents) t3 t2 t1

23. Space is viewed as in outer space (mechanics) • The 3 dimensions are of equal importance, even translated in common-sense terms • Front-back • Up-down • Left-right

24. Looking at space on earth…

25. Abstracted…

26. Space in a common-sense ontology • Space for positions/places • A horizontal plane on which objects can stand: • 2 eyes: horizontal front-back  depth • Left-right confusion (look at the mirror) • A vertical axis: up-down • Supported by gravity • Space of objects (extension) • 3 D • Combination: • We can `see’ how: • Objects can `survive’ in constructions or assemblages

27. Combining the `scientific’ with the common sense view…

28. LKIF-Core: a common sense ontology for law • Law consists of terms to interpret cases in the real (social) world • Cases are described in common sense terms • Legal technical terms are usually more strictly and explicitly defined common sense concepts • Eg liability, responsibility, permission, murder, etc. • Legislation and contracts often contain explicit definitions of terms  `ontology’ • `Aligning’ two vocabularies

29. Dependencies between types of legal knowledge Legal domain ontology

30. LKIF-Core: a common sense ontology for law • Law consists of terms to interpret cases in the real (social) world • Cases are described in common sense terms • Legal technical terms are usually more strictly and explicitly defined common sense concepts • Eg liability, responsibility, permission, murder, etc. • Legislation and contracts often contain explicit definitions of terms  `ontology’ • `Aligning’ two vocabularies…

31. …there are exceptional domains where common sense terms cannot be aligned..

32. Top-down development/KA support LKIF-Upper upper ontology mental concept social concept physical concept physical process physical object mental object content intention role action document agent norm organization “anchors” LKIF-Core legal core ontology legal action legally valid norm legal code legal person judicial organization judge normative article Dutch penal code (WvSR) criminal court perpetrator/ accomplish crime article of WvSR citizen Is-a legal domain ontology: (Dutch) criminal law Part-of

33. Common sense • By definition: the knowledge that we all share (in a culture) • Test: what can be left unsaid • `tacit’ knowledge • Descartes (Discourse de la Methode): • “Nobody complains having a lack of common sense”

34. Nobody?

35. An evolutionary perspective on acquiring c.s. concepts • Concepts enable an organism to perceive things and events as instances of objects, resp. processes • Cultural evolution: • Accumulation:`standing on the shoulders of giants’ (Newton) • Survival: passing the empirical reality test (Popper, 72) • Taxonomy of `survived’ knowledge species • Evolutionary psychology • It all started in the biology • `instincts’ (e.g. Pinker, 2008)

36. Distance sensors & locomotion • Space: the canvas • Vertical: gravity (kinesthesis) • Horizontal: stereo (f/b; l/r) • Statics: • Objects at positions • Mass, matter (substance), extension • Dynamics: change • Events with `speeds’ • Processes (causes of change) • Complementary view: background/focus • Hobbs (95, 05)

37. Predators and prey • Agents • Causation and intention (threat) • Cooperation • Differentiation (sex) • (proto-) roles

38. spatial representational system propositional representational system kinesthetic and other representational systems Enabling reflection: reification by propositions some higher mammals semantic representations (preverbal messages) FORMULATOR Joost Breuker Cicle Aranguren 2005

39. The mental world: • `Propositional’ representation: • input mode independent • `interoperability’ • Reflection • Mental life as a metaphor of the physical world • Mental processes and mental objects

40. The social world: • Configurations of roles • Dissociating agent from role • Analogue: function of physical object (device) • Role • Mental object • Reciprocal relationships • transactions • Prescriptions of behavior • Prediction by a teleological perspective • Norms • Roles are associated with positions

41. LKIF-Core: main `worlds’ • physical world • mental world • roles (= social world) • abstract world • occurrences (terms to refer to occurrences)

42. physical world • basic `natural’ concepts: energy & matter • basic defined concepts: physical object & process • both contain mixtures of energy & matter • processes are changes • transfer (changing positions) • changing value (quality; quantity) • transformation (changing type of process or object) • types of processes • mechanics: movement (moving objects & oneself) • thermo-dynamics: heat exchange, burning, (friction) • light (radiation) • chemistry: solving/mixing/cooking substances • … Joost Breuker

43. process and object force mass physical concept energy heat matter substance part-of electricity object process heat exchange form transfer movement size radiation transformation change-of-substance change-of-value Joost Breuker

44. Between death, life and mind • Biology/life: • Living and moving physical objects: agents • Agents have minds • Minds contain (memories, …), intentions • Processes initiated by agents: actions • Awareness: communication actions (cf speech acts) • Self awareness: reflection • Control over reasoning • Modeling fellow agents • Modeling discourse • …human minds… Joost Breuker

45. the mental world as a metaphor of the physical world • mappings: • energy --> emotion|motivation • matter/substance --> thought/content (information) • object ---> mental-object (concept,…) • container ----> mind, memory • process ---> mental-process (thinking, memorizing, …) • process --> action • mind/body `problem’: • person has mind; mind is container of mental entities • action: will as `force’ (energy to load the intention) Joost Breuker

46. roles • distinguishing between • role and role taker: e.g. student - person • roles imply complementary relations • speaker-hearer, student - teacher • these `complementary relations’ explain duty/rights relations in legal theories • roles are behavioural pre-scriptions • requirements for role taking (cf man taking `mother role’) • norms, prescriptions • role is subclass of mental object • role performance may be assessed against role • Bad cook, good cook, … • violating legal norm • social organization: part-of structure of roles, defining social positions Joost Breuker

47. abstract concepts • limited to purely formal, mathematical concepts • evolutionary starting with count-number (cf Lakoff & Nunez, 2000), but also point, line, size (geometry) • the `concrete’ vs `abstract’ distinction is covered in LRI-Core mainly by `physical’ vs `mental’ • mental objects: believe, thought, … • also non formal views on proposition, set, logic, rectangle, .. • mental (epistemological) roles: hypothesis, evidence,… Joost Breuker

48. and to be able to talk about occurrences… • entities = ((instances of) individual objects) • events and states of entities = (explained by processes) • situations and histories of entities= information management (episodic memory) • causation as the glue between events • on the canvas of space and time • spatial positions/areas • temporal moments/durations • ‘now’ appears to move by the arrow of time: existence of objects as trajectories in space/time Joost Breuker FOIS-2004, Torino

49. LKIF-Core development • Common-sense top-ontology (`LRI-Core’) • Collecting terms (plm 200) from legal experts (6) • Ratings (relevance, abstraction level, common-sense, etc.) • Middle out approach: identifying clusters  modules Joost Breuker

50. LKIF-Core: levels and modules