Alan Dix
Lancaster University
www.hcibook.com/alan/papers/Tamodia2002
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managing the ecology of
interaction
• rationale
• phenomena of rich interaction
• new paradigms
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overview
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the problem
• task models
– formal description
• situatedness
– unique contexts
• ethnography
– rich ecologies
bringing
them
together?
everything
formal
tasks
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option 1 – reject formalism
everything
formal
tasks
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option 2 – enforce formalism
everything
formal
tasks
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option 3 – expand and accept
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HCI – dialogue with the computer
ubicomp – no computer/artefact divide
wearable/cyborg – no computer/user divide
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dialogue with the environment
phenomena
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phenomena
•
•
•
•
•
collaboration
information
triggers
artefacts
placeholders
• situatedness
• intentional cycle
+ continuity &
duration
• already in several notations
– e.g. CTT
• add artefacts too ?
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collaboration
pre-planned cognitive model
goal  action
situated action
environment  action
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information
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control
• open loop control
– no feedback
– fragile
control
system
environment
actions
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control
• open loop control
– no feedback
– fragile
• closed loop control
– uses feedback
– robust
feedback
control
system
environment
actions
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adding information
0.
pour tea
how many
cups?
1.
boil
kettle
Plan 0:
1 then 2
when kettle boils 3 then 4
2.
get out
cups
3.
make pot
of tea
4.
pour tea
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triggers
process – what happens and order
get post from
pigeon hole
bring post
to desk
open post
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triggers
process – what happens and order
triggers – when and why
first thing in the
morning
get post from
pigeon hole
holding post
bring post
to desk
at coffee time
open post
• ethnographic studies
• as shared representation
• as focus of activity
• act as triggers, information sources, etc.
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artefacts
• 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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placeholders
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where are you?
1. controller
choose new
flight level
2. controller
tell pilot new
flight level
3. pilot
confirm new
flight level
4. pilot
ascend to
new level
5.
new flight
level achieved
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step 1. choose new flight level
1. controller
choose new
flight level
2. controller
tell pilot new
flight level
3. pilot
confirm new
flight level
4. pilot
ascend to
new level
5.
new flight
level achieved
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step 3. flight level confirmed
1. controller
choose new
flight level
2. controller
tell pilot new
flight level
3. pilot
confirm new
flight level
4. pilot
ascend to
new level
5.
new flight
level achieved
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step 5. new flight level acheived
1. controller
choose new
flight level
2. controller
tell pilot new
flight level
3. pilot
confirm new
flight level
4. pilot
ascend to
new level
5.
new flight
level achieved
• 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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continuity & duration
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intentional cycle
triggers
artefacts
memory
actions
information
and placeholders
artefacts
paradigms
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• socio-organisational Church–Turing
hypothesis
• embodied computation
• embodied interaction
• incidental interaction
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paradigms
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the socio-organisational
Church-Turing hypothesis
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• the THEOREM
– Church’s lambda calculus and Turing
machines are ‘equivalent’
• the POSTULATE
– all computation is ‘equivalent’
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the Church-Turing thesis
• are politcial, social, economic ...
but are also ...
• information processing entities
so ...
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organisations
similarities to computers and cognition
• computational power
• computational structure
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the socio-organisational ChurchTuring hypothesis
• computer: program and data
• organisation: process and information
plus …
• computer data:
LTM, STM, program counter
• organisation: ????
files, papers … placeholders
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the organisation as a computer
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parallels
process
data
placeholder
computer
cog sci
organisation
program
procedural
memory
processes
data
LTM
files
program
counter
STM,
activation
location of
artefacts
stimuli
triggers
initiative interrupts,
events
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parallels
process
data
placeholder
computer
cog sci
organisation
program
procedural
memory
processes
data
LTM
files
program
counter
STM,
activation
location of
artefacts
stimuli
triggers
???
people
initiative interrupts,
events
interpretation
???
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embodied computation
the world is full of computation
 cognitive
 social
 economic
this helps us understand the world
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ubiquity of compuation
computation happens in the world
 memory
 networks
 processors
this helps us understand computation
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physicality of compuation
• 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 computation
some examples
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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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embodied 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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incidental interaction
• model main purposeful activity
– use to design sensors
• model activity to be aided/enhanced
– use to design actuators
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? task analysis
winding up
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• 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
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final thoughts …