managing the ecology of interaction

1. managing the ecology of interaction Alan Dix Lancaster University www.hcibook.com/alan/papers/Tamodia2002

2. overview • rationale • phenomena of rich interaction • new paradigms

3. bringing themtogether? the problem • task models • formal description • situatedness • unique contexts • ethnography • rich ecologies

4. option 1 – reject formalism everything formal tasks

5. option 2 – enforce formalism formal tasks everything

6. option 3 – expand and accept everything formal tasks

7. HCI – dialogue with the computer

8. dialogue with the environment ubicomp – no computer/artefact divide wearable/cyborg – no computer/user divide

9. phenomena

10. collaboration information triggers artefacts placeholders situatedness intentional cycle continuity & duration phenomena

11. collaboration • already in several notations • e.g. CTT • add artefacts too ?

12. information pre-planned cognitive model goal  action situated action environment  action

13. controlsystem environment actions control • open loop control • no feedback • fragile

14. feedback controlsystem environment actions control • open loop control • no feedback • fragile • closed loop control • uses feedback • robust

15. adding information

16. triggers process – what happens and order get post frompigeon hole bring postto desk open post

17. triggers process – what happens and order triggers – when and why first thing in the morning holding post at coffee time get post frompigeon hole bring postto desk open post

18. artefacts • ethnographic studies • as shared representation • as focus of activity • act as triggers, information sources, etc.

19. placeholders • knowing where you are in a process • like a program counter • coding: • memory • explicit (e.g. to do list) • in artefacts

20. where are you?

21. step 1. choose new flight level

22. step 3. flight level confirmed

23. step 5. new flight level acheived

24. continuity & duration • system models – event centric • status–event analysis • continuous time (status) and discrete (events) • many generic issues and phenomena • task models: • in the annotations and descriptions • concurrency – true or interleaved?

25. intentional cycle memory triggers artefacts artefacts actions information and placeholders

26. paradigms

27. paradigms • socio-organisational Church–Turing hypothesis • embodied computation • embodied interaction • incidental interaction

28. the socio-organisationalChurch-Turing hypothesis

33. the Church-Turing thesis • the THEOREM • Church’s lambda calculus and Turing machines are ‘equivalent’ • the POSTULATE • all computation is ‘equivalent’

34. organisations • are politcial, social, economic ... but are also ... • information processing entities so ...

35. the socio-organisational Church-Turing hypothesis similarities to computers and cognition • computational power • computational structure

36. the organisation as a computer • computer: program and data • organisation: process and information plus … • computer data: LTM, STM, program counter • organisation: ???? files, papers … placeholders

37. parallels

38. parallels

39. embodied computation

40. ubiquity of compuation the world is full of computation • cognitive • social • economic this helps us understand the world

41. physicality of compuation computation happens in the world • memory • networks • processors this helps us understand computation

42. embodied computationsome examples • computation is incremental • interaction not Magnus Magnusson • pointers take space • where log space comes from • space means time • o(N) memory takes 3√N time • representation not information • importance of interpretation

43. embodied interaction

44. embodied interaction • Paul Dourish’s term • focus on: • tangible computing • social computing • users create meaning • designers give them the means • where does task analysis fit in?

45. incidental interaction

46. incidental interaction • traditional interaction – purposeful • user as controller • system as slave • incidental interaction • user acts for one purpose • system observes and acts

47. incidental interaction • traditional interaction – purposeful • user as controller, system as slave • incidental interaction • system observes and acts, not user’s purpose • examples: • car lights • auto-flush toilet • intelligent homes

48. ? task analysis • model main purposeful activity • use to design sensors • model activity to be aided/enhanced • use to design actuators

49. winding up

50. final thoughts … • ecologically valid task modelling • incorporate rich phenomena • but also understand limits • role? • normative or normal? • definitive process or descriptive grammar • main task or subsidiary task