2. Motivation
• Traditionally:
– Systems developed for an idealized/homogenized user or
categories of users
• Possibly with some tailoring
• Increasingly:
– Systems need to be tailored to individual users and their
contexts and to adapt as users’ needs evolve
– Recent trends towards self-adaptive systems reflect this
• Our aim:
– A model-based framework for personal and contextual
modeling
3. Personal Contextual Knowledge
People have …
…. information describing them
… and information held by them
Some of this information changes over time and according
to context.
Is a journalist
Values privacy
4. General
stakeholder
requirements
Spacial change
Business and domain
evolution, expert users, ..
Culture and localisation,
interaction language, …
User
characteristics
requirements
Individual user skill
and ability, …
Physical context,
social context, …
Personal
goals
Attain individual
goals
Location, social
context
A two-layer framework
5. User Characteristics
• The information describing someone
• Includes their skills and knowledge but also cognitive,
physical and perceptual abilities.
– e.g. Truck driver has a commercial driving license (skill) but
also myopia (perceptual ability)
• May change with time
– Myopia may get worse, spacial orientation skills may decline
as driver ages
• May change with context
– Driving around home town vs. driving around an unfamiliar
city, reactions and spacial awareness when fresh vs. when
tired
6. User Characteristics (contd.)
• Where useful?
– Depends on application (of course), e.g.:
• Socio-technical systems involving physical action, or action in
virtual environments that might lack physical cues
• Users of assistive technologies in which each user will need
care tailored to their condition(s)
– Systems tailored to skills and abilities, but also adapt as
these change over time e.g.:
• Skills improve
• User’s condition progresses
7. Personal Goals
• The information held by someone, but also their
attitudes and preferences
• Values are key components of personal goal
attainment.
9. Personal Goals (cont.d)
• The information held by someone, but also their
attitudes and preferences
• Values are key components of personal goal
attainment.
• Values tend to be less time-variant than personal
characteristics
• Values are a diverse set of properties but their
usefulness lies in being able to understand their
impact on personal goal attainment, e.g.:
– concerns about privacy is something social network systems
have to deal with
10. The Framework: broad
principles
• User characteristics used as a checklist to identify
potential obstacles to system goal satisfaction
• In the personal goals layer, values may represent
“weak obstacles”; probabilities that user behaviour
will inhibit attainment of system goals
11. Case Study
• An Ambient Assisted Living System
• Two users
– Mary
– Mary’s carer
• Mary has:
– Limited mobility
• Able to live at home with assistance
– Mild Cognitive Impairment
• May forget things
12. AAL KAOS Goal Model 1
Achieve[Release
Dose]
Achieve[
MedicineTaken]
Maintain[Is
Healthy]
Achieve[Correct
MedicineDose]
Dispenser
Mary
Top level
system
goal
An
expectation
Human
agent
System
agent
A
requirement
13. Personal Characteristics
• Mary’s key characteristic is her MCI
– She might forget to take her medicine
• Leads to the obstacle Forgets to Take Medicine
• Mary’s MCI will probably get worse over time
15. AAL KAOS Goal Model 3
Achieve[Release
Dose]
Achieve[
MedicineTaken]
Maintain[Is
Healthy]
Achieve[Correct
MedicineDose]
Dispenser
Mary
Forgets to
take medicine
Underdose
Overdose
Achieve[Prompt
ToTakeMedicine]
Achieve[Remind
MedicineUntaken]
Maintain[Monitor
DispenserTray]
AAL
AAL
Achieve[Detect
UntakenMedicine]
Mitigates
Mary wants
to maintain
her health
Domain
assumption
16. So far …
• We’ve used one of Mary’s personal characteristics to
guide obstacle analysis for the system goal model
• Now we will analyse Mary’s personal goals to
investigate whether there are any further (“weak”)
obstacles that arise from Mary’s values and that need
to be mitigated.
• We use Mary’s values to help understand softgoals;
system qualities
• We start by eliciting these system qualities and
modeling them as softgoals
17. AAL KAOS Goal Model 4
Achieve[Release
Dose]
Achieve[
MedicineTaken]
Forgets to
take medicine
Underdose
Maintain[Is
Healthy]
Achieve[Correct
MedicineDose]
Overdose
Dispenser
Achieve[Prompt
ToTakeMedicine]
Achieve[Remind
MedicineUntaken]
Maintain[Monitor
DispenserTray]
Mary
AAL
AAL
Achieve[Detect
UntakenMedicine]
Mary wants
to maintain
her health
+
-
Avoid
intervention
Minimize
intrusion
18. Effect of Mary’s values on
Minimize Intrusion quality
Minimize
intrusion
frustration resentment
emotional
resonse
cooperation openness
+
+
=
+
=
Mary is open and cooperative. This
potentially gives hare a neutral attitude to
intrusive interventions by the AAL
19. Effect of Mary’s values on
Minimize Intrusion quality
Minimize
intrusion
frustration resentment
emotional
resonse
cooperation openness
+
+
=
+
=
However, Mary suffers feelings of frustration at her
condition and may feel resentment that interventions are
needed. This strengthens her intent to avoid
interventions but may lead her to ignore or attempt to
subvert reminders
This should lead us to mitigate
the risks – perhaps by careful
design of the reminders – e.g. to
make them empathic
20. Uncertainty 1
• Mary’s values may be estimated in a number of ways:
– Online tests
– Estimates from her carer
– Estimates from domain experts
• Clearly there will be significant uncertainty about the
nature and strength of her values
21. Uncertainty 2
Minimize
intrusion
frustration resentment
emotional
response
cooperation openness
+
+
=
+
=
• Is this the right set of values for Mary?
• Do they have the same or different relative weights?
• Are the propagated values (the ‘+’, etc.) the right ones?
• These are probably best understood probabilistically
• Baysian reasoning may be of help here.
22. Time and Context
• So far we have not considered time or context
• But these might be relevant, e.g.:
– Mary’s condition might progress and reminders might have
to become more frequent
– There may be contexts in which Mary more commonly
forgets to take her medicine
• Monitoring (A key component of an adaptive system)
could be used to discover these.
• The framework should help us identify what to
monitor
23. Next Steps
• We are applying the framework to the EPSRC SAMS
project1
– Software Architecture for Mental health Self management
• SAMS aims to encourage self-referral for people with
the early signs of dementia
• SAMS will apply text and data mining techniques to
look for signs of Mild Cognitive Impairment by
passive monitoring of peoples’ interaction with their
computer 1EPSRC grant EP/K015796/1
24. Conclusions
• We are interested in how to systematize the design of
systems that have a focus on the individual user
• We propose a two-layer framework based on well-
developed models of personal characteristics and
personal goals
• We use these to help us identify strong and weak
obstacles to attainment of system and user goals,
using goal modeling.
• Still to do:
– Validate the sets of characteristics and values
– Develop means of reasoning about their effects on goal
attainment
