tamodia 2002 managing the ecology of interaction alan dix lancaster university
TRANSCRIPT
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managing the ecology of interaction
Alan Dix
Lancaster Universitywww.hcibook.com/alan/papers/Tamodia2002
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overview
• rationale
• phenomena of rich interaction
• new paradigms
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the problem
• task models– formal description
• situatedness– unique contexts
• ethnography– rich ecologies
bringingthem
together?
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option 1 – reject formalism
everything
formaltasks
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option 2 – enforce formalism
everything
formaltasks
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option 3 – expand and accept
everything
formaltasks
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HCI – dialogue with the computer
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dialogue with the environment
ubicomp – no computer/artefact divide
wearable/cyborg – no computer/user divide
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phenomena
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phenomena
• collaboration
• information
• triggers
• artefacts
• placeholders
• situatedness
• intentional cycle
+ continuity & duration
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collaboration
• already in several notations– e.g. CTT
• add artefacts too ?
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information
pre-planned cognitive model
goal action
situated action
environment action
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control
• open loop control– no feedback– fragile
controlsystem
environmentactions
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control
• open loop control– no feedback– fragile
• closed loop control– uses feedback– robust
controlsystem
environmentactions
feedback
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adding information
boilkettle
get outcups
make potof tea pour tea
pour teaPlan 0: 1 then 2 when kettle boils 3 then 4
0.
1. 2. 3. 4.
how manycups?
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triggers
process – what happens and order
get post frompigeon hole
bring postto desk
open post
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triggers
process – what happens and order
triggers – when and why
first thing in themorning
holding post at coffee time
get post frompigeon hole
bring postto desk
open post
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artefacts
• ethnographic studies
• as shared representation
• as focus of activity
• act as triggers, information sources, etc.
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placeholders
• knowing where you are in a process– like a program counter
• coding:– memory– explicit (e.g. to do list)– in artefacts
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where are you?
1. controllerchoose newflight level
2. controllertell pilot newflight level
3. pilotconfirm newflight level
4. pilotascend tonew level
5.new flight
level achieved
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step 1. choose new flight level
1. controllerchoose newflight level
2. controllertell pilot newflight level
3. pilotconfirm newflight level
4. pilotascend tonew level
5.new flight
level achieved
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step 3. flight level confirmed
1. controllerchoose newflight level
2. controllertell pilot newflight level
3. pilotconfirm newflight level
4. pilotascend tonew level
5.new flight
level achieved
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step 5. new flight level acheived
1. controllerchoose newflight level
2. controllertell pilot newflight level
3. pilotconfirm newflight level
4. pilotascend tonew level
5.new flight
level achieved
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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?
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intentional cycle
artefacts artefacts
informationand placeholders
actions
triggersmemory
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paradigms
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paradigms
• socio-organisational Church–Turing hypothesis
• embodied computation
• embodied interaction
• incidental interaction
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the socio-organisationalChurch-Turing hypothesis
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the Church-Turing thesis
• the THEOREM– Church’s lambda calculus and Turing
machines are ‘equivalent’
• the POSTULATE– all computation is ‘equivalent’
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organisations
• are politcial, social, economic ...
but are also ...
• information processing entities
so ...
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the socio-organisational Church-Turing hypothesis
similarities to computers and cognition
• computational power
• computational structure
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the organisation as a computer
• computer: program and data
• organisation: process and information
plus …
• computer data:LTM, STM, program counter
• organisation: ????files, papers … placeholders
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parallels
computer cog sci organisation
process program proceduralmemory
processes
data data LTM fil es
placeholder programcounter
STM,activation
location ofartefacts
initiative interrupts,events
stimuli triggers
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parallels
computer cog sci organisation
process program proceduralmemory
processes
data data LTM fil es
placeholder programcounter
STM,activation
location ofartefacts
initiative interrupts,events
stimuli triggers
interpretation ??? ??? people
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embodied computation
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ubiquity of compuation
the world is full of computation cognitive social economic
this helps us understand the world
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physicality of compuation
computation happens in the world memory networks processors
this helps us understand computation
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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
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embodied interaction
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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?
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incidental interaction
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incidental interaction
• traditional interaction – purposeful – user as controller– system as slave
• incidental interaction– user acts for one purpose– system observes and acts
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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
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? task analysis
• model main purposeful activity– use to design sensors
• model activity to be aided/enhanced– use to design actuators
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winding up
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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