Session 1 Lecture 2 PACT A Framework for Designing Interactive Systems
Md. Saifuddin Khalid
KANDIDATUDDANNELSEN I INFORMATIONSTEKNOLOGI,
IT OG LÆRING, MED SPECIALISERING I
Modulets placering: 8. semester
Modulets omfang: 5 ECTS
Monday, 06 February, 2017
6 February 2017 Aalborg University 1
Interaction Design Course
Session 1: Lecture 2
About PACT Framework
An essential part of our approach to designing
interactive systems is that it should put people first; it
should be human-centred.
We use the acronym PACT (People, Activities,
Contexts, Technologies) as a useful framework for
thinking about a design situation.
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(Benyon, 2010, p. 26)
Scoping a problem with PACT
A PACT analysis is useful for both analysis and design
activities: understanding the current situation, seeing where
possible improvements can be made or envisioning future
To do a PACT analysis the designer simply scopes out the
variety of Ps, As, Cs and Ts that are possible, or likely, in a
PACT analysis can be viewed as the “preliminary
requirements analysis”, which is used as part of the first
phase in traditional software engineering process or “product
vision” in Scrum or Lean.
This can be done by using various methods and tools. E.g.
brainstorming, observations, interviews and workshops.
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Activities and Technologies
Technologies support a
wide range of people to
undertake various activities
in different contexts.
Activities (and the
of activity’ within which
they take place) establish
technologies that in turn
offer opportunities that
change the nature of
activities. And so the cycle
continues as the changed
activity results in new
technologies and so on.6 February 2017 4Aalborg University
The changing nature of interaction
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Figure. The changing nature of telephoning activity as technology
advances (Benyon, 2010, p.28)
Interaction designers begin with the differences
among the users and their interactions.
Benyon (2010) discussed these in part IV of the book in
details. This lecture will cover these briefly.
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People: Physical differences
People differ in
Physical characteristics, e.g. height and weight
Five senses, i.e. sight, hearing, touch, smell and taste.
Case: International approaches to bicycle and pedestrian
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The term ‘ergonomics’ was coined in 1948 to describe the
study of the relationships between people and their
People: Anthropometrics, the measurement of
Ambient environment (temperature, humidity,
atmospheric pressure, light levels, noise and so on)
Working environment (the design of machines, health
and safety issues – e.g. hygiene, toxicology, exposure to
ionizing radiation, microwaves, etc.).
Ergonomics draws on anatomy and physiology, various
aspects of psychology (e.g. physiological and experimental),
physics, engineering and work studies among others.
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People: Ergonomics (Cont.)
Ergonomic designs include but not limited to
office furniture: chairs, desks, lights, footrests and so forth)
office equipment, for example keyboards, monitor stands
and wrist rests.
Search “ergonomic devices” in images.google.com for
Possibilities are redefined with finding on ergonomics. E.g.
interactions with mobile resulted the use of thumbs to ring
doorbells, push doors and point.
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People: Psychological differences
Language differences: In the USA a tick is used for
acceptance and a cross for rejection, but in Britain a
tick or a cross can be used to show acceptance (e.g. a
cross on a voting paper).
Individual differences. E.g. OCEAN: Openness to
Experience, Conscientiousness, Extraversion,
Agreeableness, and Neuroticism.
Attention and memory in relation to individual needs
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People: Mental models
A person’s ‘mental model’ (e.g. Norman, 1998) of a
device: If something goes wrong they will not know
why and will not be able to recover.
Designer must design things so that people will form
correct and useful mental models of how they work
and what they do.
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People: Mental models (Cont.)
Mental models are incomplete. People will
understand some parts of a system better than
People can ‘run’ (or try out) their models when
required, but often with limited accuracy.
Mental models are unstable – people forget
Mental models do not have firm boundaries:
similar devices and operations get confused
with one another.
Mental models are unscientific, exhibiting
Mental models are parsimonious. People are
willing to undertake additional physical
operations to minimize mental effort, e.g.
people will switch off the device and start again
rather than trying to recover from an error.
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The nature of mental
models of interactive
systems (Norman, 1983)
People: Social differences
Novice and expert users of a technology will typically
have very different levels of knowledge and hence
requirements for design feature
Designing for homogeneous groups of people – groups
who are broadly similar and want to do much the same
things – is quite different from designing for
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10 important characteristics of activities that designers
need to consider. First and foremost, the overall
purpose of the activity.
Temporal aspects, e.g. how regular or infrequent
The nature of the content.
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Activities in contexts can be analyzed by three types of
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Figure. Interactions in different working contexts
Last, analyzing technology requirements as part of
Input (i.e. data and instructions)
Output (i.e. mainly vision, hearing and touch)
Content (i.e. data and its forms)
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Benyon, David. (2010). Designing Interactive
Systems: A Comprehensive Guide to HCI and
Interaction Design. 2nd ed. Harlow, England ; N.Y:
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