1. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 1 Contextor: a Computational Model for Contextual Information Joëlle Coutaz, Gaëtan Rey CLIPS-IMAG, Université Joseph Fourier, Grenoble, France James L. Crowley GRAVIR-IMAG, INPG, INRIA, Grenoble, France

2. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 2 Context for Ubicomp: no Consensus, but some Lessons Lesson1: Context can only be defined in relation to a purpose –As for us: Computational perception (user’s implicit actions, environment sensing) Lesson 2: Context is an information space that serves interpretation –As for us: Interpretation by the system for serving users Lesson 3: Context is an information space that is shared –As for us: Common ground between a system and a user Lesson 4: Context is an ever-ending information space: it evolves –As for us: Distinction between a situation and composition of situations

3. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 3 Context for Ubicomp: no Consensus, but some Lessons Lesson1: Context can only be defined in relation to a purpose –As for us: Computational perception (user’s implicit actions, environment sensing) Lesson 2: Context is an information space that serves interpretation –As for us: Interpretation by the system for serving users Lesson 3: Context is an information space that is shared –As for us: Common ground between a system and a user Lesson 4: Context is an ever-ending information space: it evolves –As for us: Distinction between a situation and composition of situations User’s Context System’s Context

4. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 4 Context for Ubicomp: no Consensus, but some Lessons Lesson1: Context can only be defined in relation to a purpose –As for us: Computational perception (user’s implicit actions, environment sensing) Lesson 2: Context is an information space that serves interpretation –As for us: Interpretation by the system for serving users Lesson 3: Context is an information space that is shared –As for us: Common ground between a system and a user Lesson 4: Context is an ever-ending information space: it evolves –As for us: Distinction between a situation and composition of situations User’s Context System’s Context

5. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 5 Context for Ubicomp: no Consensus, but some Lessons Lesson1: Context can only be defined in relation to a purpose –As for us: Computational perception (user’s implicit actions, environment sensing) Lesson 2: Context is an information space that serves interpretation –As for us: Interpretation by the system for serving users Lesson 3: Context is an information space that is shared –As for us: Common ground between a system and a user Lesson 4: Context is an ever-ending information space: it evolves

6. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 6 Outline Ontology for computational perception Computational model: contextor

7. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 7 Ontology … Domain (world) = a network of states S2 S6 S1 S S3 S4

8. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 8 Ontology … Domain (world) = a network of states linked by actions S2 S6 S1 S S3 S4 a1 a2 a3 a2 a3

9. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 9 Ontology … Domain (world) = a network of states linked by actions State = a predicate function over observables S2 S6 S1 S P(O 1, O 2, …, O n ) S3 S4 a1 a2 a3 a2 a3 O1O1 O2O2 OmOm

10. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 10 Ontology … Domain (world) = a network of states linked by actions State = a predicate function over observables Goal state = a desired state S2 S6 Goal state S1 S P(O 1, O 2, …, O n ) S3 S4 a1 a2 a3 a2 a3 O1O1 O2O2 OmOm

11. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 11 Ontology … Domain (world) = a network of states linked by actions State = a predicate function over observables Goal state = a desired state Task =, i.e., no plan S2 Current state S6 Goal state S1 S P(O 1, O 2, …, O n ) S3 S4 a1 a2 a3 a2 a3 O1O1 O2O2 OmOm

12. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 12 Ontology … Domain (world) = a network of states linked by actions State = a predicate function over observables Goal state = a desired state Task =, i.e., no plan Activity = = S2 Current state S6 Goal state S1 S P(O 1, O 2, …, O n ) S3 S4 a1 a2 a3 a2 a3 O1O1 O2O2 OmOm

13. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 13 Ontology … Tasks involve entities (e.g., a table, pen, color) Entity E1 Table Entity E2 Pen

14. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 14 Ontology … Tasks involve entities (e.g., a table, pen, color) Entity = a grouping of observables Entity E1 Table O1O1 O2O2 OmOm OlOl OkOk OnOn Entity E2 Pen

15. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 15 Ontology … Tasks involve entities (e.g., a table, pen, color) Entity = a grouping of observables Entities may have a role = a function relative to a task that is satisfied by an entity, e.g., sitting surface Role pointer {E2} Entity E1 Table Role Sitting surface {E1} O1O1 O2O2 OmOm OlOl OkOk OnOn Entity E2 Pen

16. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 16 Ontology … Tasks involve entities (e.g., a table, pen, color) Entity = a grouping of observables Entities may have a role = a function relative to a task that is satisfied by an entity, e.g., sitting surface Entities may have relations Role pointer {E2} Entity E1 Table Role Sitting surface {E1} O1O1 O2O2 OmOm OlOl OkOk OnOn Entity E2 Pen On top

17. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 17 Ontology… Context(U,T) = a set of roles and relations between entities for the performance of T by U C1 R1R2 r

18. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 18 Ontology… Context(U,T) = a set of roles and relations between entities for the performance of T by U Context change = the set of roles changes C2 R1R2 r C1 R1R2 r New role R3

19. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 19 Ontology… Context(U,T) = a set of roles and relations between entities for the performance of T by U Context change = the set of roles changes and/or the set of relations changes C2 R1R2 r C1 R1R2 r C3 R1R2 r New role R3 New relation r’

20. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 20 Ontology… Context(U,T) = a set of roles and relations between entities for the performance of T by U Context change = the set of roles changes and/or the set of relations changes Tasks and activities happen in a network of contexts C2 R1R2 r C1 R1R2 r C3 R1R2 r R3 r’

21. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 21 Ontology… Context(U,T) = a set of roles and relations between entities for the performance of T by U Context change = the set of roles changes and/or the set of relations changes Tasks and activities happen in a network of contexts Context (U,T) = a network of situations that share the same set of Roles and Relations C2 R1R2 r C1 R1R2r C3 R1R2 r R3 r’r’ Network of Situations

22. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 22 Ontology … Within a context, a situation is a configuration of –A set of entities –Assignments of roles to entities –Relations between these entities S1 R1R2 e2 e1 r e2 e1 C1

23. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 23 Ontology … Within a context, a situation changes when –assignments of entities to roles changes S2 R1R2 e1e2 e1 Assignment to Role has changed S1 R1R2 e2 e1 r e2 e1 C1

24. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 24 Ontology … Within a context, a situation changes when –assignments of entities to roles changes –relations between the entities change S2 R1R2 e1e2 r e1 S3 R1R2 e2e1 r e2 Assignment to Role has changed Relation has changed S1 R1R2 e2 e1 r e2 e1 C1

25. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 25 Ontology … Within a context, a situation changes when –assignments of entities to roles changes –relations between the entities change –The set of entities changes S2 R1R2 e1e2 r e1 S4 R1R2 e2e1 r e2e1 S3 R1R2 e2e1 r e2 Assignment to Role has changed Relation has changed New entity S1 R1R2 e2 e1 r e2 e1 e3 C1

26. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 26 Computational model: the Contextor … A computational abstraction –Two functional facets Transformation: Data (Type X) +meta-data -> Data (Type Y) +meta-data Control: adaptation of behavior –Synchronous and asynchronous ports

27. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 27 Computational model: the Contextor … Instantiation 1: data as observables

28. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 28 Computational model: the Contextor … Instantiation2: from Observables to Entity

29. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 29 Computational model: the Contextor … Instantiation3: from entities to relation between entities

30. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 30 Contextors composition Data flow model Hierarchical levels (HL) Dependency chain Application 1 Application 2 HL = 0 HL = 1 HL = 2

31. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 31 Contextors: properties Reflexivity – Ability to describe its behavior – Ability tomodify its behavior Remanence – Ability to sleep, to be saved then to restart execution Context => federation of contextors New situation => reconfiguration of the contextors within the federation New context => new federation of contextors

32. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 32 Contextors: global architectural picture Extension of the ARCH model (D.Salber) Process style (Contextor) Data style (Blackboard)

33. Concepts&Models for Ubicomp, Ubicomp02, Goteborg, Sept. 29th, 2002 33 Contextor: a Computational Model for Contextual Information Joëlle Coutaz, Gaëtan Rey CLIPS-IMAG, Université Joseph Fourier, Grenoble, France James L. Crowley GRAVIR-IMAG, INPG, INRIA, Grenoble, France