Week 5 lecture for im2044 2012-2013

1. IM2044 – Week 6: Lecture
Dr. Andres Baravalle
1

2. Interaction design
• The next slides are based on the
companion slides for the textbook
• By the end of this week, you should have
studied all chapters of the textbook up to
chapter 10
• Today we will covering chapters 9-10.
2

3. Overview
• What is Interaction Design?
– Importance of involving users
– Degrees of user involvement
– What is a user-centered approach?
• Some practical issues:
–
–
–
–
Who are the users?
What are ‘needs’?
Where do alternatives come from?
How do you choose among
alternatives?
3

4. What is Interaction Design?
• It is a process:
– A goal-directed problem solving activity informed by
intended use, target domain, materials, cost, and
feasibility
– A creative activity
– A decision-making activity to balance trade-offs
• Four approaches: user-centered design,
activity-centered design, systems design,
and genius design
4

5. Importance of involving users
• Expectation management
–
–
–
–
Realistic expectations
No surprises, no disappointments
Timely training
Communication, but no hype
• Ownership
– Make the users active stakeholders
– More likely to forgive or accept problems
– Can make a big difference to acceptance and
success of product
5

6. Degrees of user involvement
• Member of the design team
– Full time: constant input, but lose touch with
users
– Part time: patchy input, and very stressful
– Short term: inconsistent across project life
– Long term: consistent, but lose touch with users
• Dissemination devices, as newsletters
– Reach wider selection of users
– Need communication both ways
• User involvement after product is released
• Combination of these approaches
6

7. What is a user-centered
approach?
• User-centered approach is based on:
– Early focus on users and tasks: directly studying
user characteristics (cognitive, behavioural,
anthropomorphic & attitudinal)
– Empirical measurement: users’ reactions and
performance to scenarios, manuals, simulations &
prototypes are observed, recorded and analysed
– Iterative design: when problems are found in user
testing, fix them and carry out more tests
7

8. Interaction design activities
•
•
•
•
Establishing requirements
Designing alternatives
Prototyping
Evaluating
8

9. A simple interaction design
lifecycle model
•
•
•
•
•
Who are the users?
What do we mean by ‘needs’?
How to generate alternatives
How to choose among alternatives
How to integrate interaction design
activities with other models?
9

10. Who are the
users/stakeholders?
• Not as obvious as you think:
–
–
–
–
–
Those who interact directly with the product
Those who manage direct users
Those who receive output from the product
Those who make the purchasing decision
Those who use competitor’s products
• Three categories of user (Eason, 1987):
– Primary: frequent hands-on
– Secondary: occasional or via someone else
– Tertiary: affected by its introduction, or will influence
its purchase
10

11. Who are the stakeholders?
Check-out operators
• Suppliers
• Local shop
owners
Customers
Managers and owners
11

12. What do we mean by ‘needs’?
• Users rarely know what is possible
• Users (typically) can’t tell you what they ‘need’ to help
them achieve their goals
• Instead, look at existing tasks:
–
–
–
–
Their context
What information do they require?
Who collaborates to achieve the task?
Why is the task achieved the way it is?
• Envisioned tasks:
– can be rooted in existing behaviour
– can be described as future scenarios
12

13. How to generate alternatives
• Humans stick to what they know works
– Considering alternatives is important to ‘break out of
the box’
• Designers are trained to consider alternatives,
software developers generally are not
• How do you generate alternatives?
– ‘Flair and creativity’: research and synthesis
– Seek inspiration: look at similar products or look at
very different products
13

14. How to choose among
alternatives
• Evaluation with users or with peers, e.g.
prototypes
• Technical feasibility: some not possible
• Quality thresholds: usability goals lead to
usability criteria set early on and check regularly
– Safety: how safe?
– Utility: which functions are superfluous?
– Effectiveness: appropriate support? task coverage,
information available
– Efficiency: performance measurements
14

15. How to choose among
alternatives
Test the alternatives!
15

16. How to integrate interaction
design in other models?
• Agile software development is one option:
– Have development and design running in
separate tracks
– Maintain a coherent vision of the interface
architecture
16

17. Software requirements: what,
how and why
• What:
1. Understand as much as possible
about users, task, context
2. Produce a stable set of
requirements
• How:
Data gathering activities
Data analysis activities
Expression as ‘requirements’
All of this is iterative
17

18. Software requirements: what,
how and why (2)
•Why:
Requirements
definition: the
stage where
failure occurs
most commonly
•Getting
requirements right
is crucial
18

19. Volere shell
19

20. Volere requirements template
20

21. Establishing requirements
• What do users want? What do users ‘need’?
• Requirements need clarification, refinement,
completion, re-scoping
• Input: requirements document (maybe)
• Output: stable requirements
• Why ‘establish’?
• Requirements arise from understanding users’
needs
• Requirements can be justified & related to data
21

22. Different kinds of requirements
• Functional:
—What the system should do
—Historically the main focus of
requirements activities
• (Non-functional: memory size, response
time...)
• Data:
—What kinds of data need to be stored?
—How will they be stored (e.g.
database)?
22

23. Different kinds of requirements (2)
Environment or context of use:
— Physical: dusty? noisy? vibration? light?
heat? humidity? …. (e.g. OMS insects, ATM)
— Social: sharing of files, of displays, in
paper, across great distances, work
individually, privacy for clients
— Organisational: hierarchy, IT department’s
attitude and remit, user support,
communications structure and infrastructure,
availability of training
23

24. An extreme example
24

25. Different kinds of requirements (3)
• Users: Who are they?
— Characteristics: ability, background, attitude
to computers
— System use: novice, expert, casual, frequent
— Novice: step-by-step (prompted),
constrained, clear information
— Expert: flexibility, access/power
— Frequent: short cuts
— Casual/infrequent: clear instructions, e.g.
menu paths
25

26. What are the users’
capabilities?
• Humans vary in many dimensions:
– Size of hands may affect the size and positioning of
input buttons
– Motor abilities may affect the suitability of certain
input and output devices
– Height, if designing a physical kiosk
– Strength - a child’s toy requires little strength to
operate, but greater strength to change batteries
– Disabilities (e.g. sight, hearing, dexterity)
26

27. Kinds of requirements
• What factors (environmental, user,
usability) would affect the following
systems?
• Self-service filling and payment system
for a petrol (gas) station
• On-board ship data analysis system for
geologists searching for oil
• Fashion clothes website
27

28. Personas (stereotypes)
• Capture user characteristics
– Not real people, but synthesised from real
user characteristics
– Should not be idealised
– Bring them to life with a name, characteristics,
goals, personal background
• Develop multiple personas
28

29. Personas
29

30. Data gathering for requirements
Interviews:
— Props, e.g. sample scenarios of use,
prototypes, can be used in interviews
— Good for exploring issues
— But are time consuming and may be
infeasible to visit everyone
Focus groups:
— Group interviews
— Good at gaining a consensus view and/or
highlighting areas of conflict
— But can be dominated by individuals
30

31. Data gathering for requirements
(2)
Questionnaires:
— Often used in conjunction with other
techniques
— Can give quantitative or qualitative data
— Good for answering specific questions from
a large, dispersed group of people
Researching similar products:
— Good for prompting requirements
31

32. Data gathering for requirements
(3) observation:
Direct
— Gain insights into stakeholders’ tasks
— Good for understanding the nature and
context of the tasks
— But, it requires time and commitment
from a member of the design team, and
it can result in a huge amount of data
Indirect observation:
— Not often used in requirements activity
— Good for logging current tasks
32

33. Data gathering for requirements
(4)
Studying documentation:
— Procedures and rules are often written
down in manuals
— Good source of data about the steps
involved in an activity, and any
regulations governing a task
— Not to be used in isolation
— Good for understanding legislation, and
getting background information
— No stakeholder time, which is a limiting
factor on the other techniques
33

34. Problems with data gathering
(1)
• Identifying and involving stakeholders:
users, managers, developers, customer reps?,
union reps?, shareholders?
• Involving stakeholders: workshops, interviews,
workplace studies, co-opt stakeholders onto the
development team
• Getting ‘real’ users, not managers:
traditionally a problem in software engineering
34

35. Problems with data gathering
(2)
• Requirements management: version control, ownership
• Communication between parties:
– Within development team
– With customer/user
– Between users… different parts of an organisation
use different terminology
• Domain knowledge distributed and implicit:
– Difficult to dig up and understand
– Knowledge articulation: how do you walk?
• Availability of key people
35

36. Problems with data gathering
(3)
• Political problems within the organisation
• Dominance of certain stakeholders
• Economic and business environment
changes
• Balancing functional and usability
demands
36

37. Some basic guidelines
• Focus on identifying the stakeholders’
needs
• Involve all the stakeholder groups
• Involve more than one representative
from each stakeholder group
• Use a combination of data gathering
techniques
37

38. Some basic guidelines (2)
• Support the process with props such as
prototypes and task descriptions
• Run a pilot session
• You will need to compromise on the data you
collect and the analysis to be done, but before
you can make sensible compromises, you need
to know what you’d really like
• Consider carefully how to record the data
38

39. Data interpretation and analysis
• Start soon after data gathering session
• Initial interpretation before deeper
analysis
• Different approaches emphasize different
elements e.g. class diagrams for objectoriented systems, entity-relationship
diagrams for data intensive systems
39

40. Task descriptions
• Scenarios
― An informal narrative story, simple, ‘natural’,
personal, not generalisable
• Use cases
— Assume interaction with a system
— Assume detailed understanding of the
interaction
• Essential use cases
— Abstract away from the details
— Does not have the same assumptions as use
cases
40

41. Task analysis
• Task descriptions are often used to envision new
systems or devices
• Task analysis is used mainly to investigate an existing
situation
• It is important not to focus on superficial activities
– What are people trying to achieve?
– Why are they trying to achieve it?
– How are they going about it?
• Many techniques, the most popular is Hierarchical Task
Analysis (HTA)
41

42. Hierarchical Task Analysis
• Involves breaking a task down into subtasks,
then sub-sub-tasks and so on. These are
grouped as plans which specify how the tasks
might be performed in practice
• HTA focuses on physical and observable
actions, and includes looking at actions not
related to software or an interaction device
• Start with a user goal which is examined and the
main tasks for achieving it are identified
• Tasks are sub-divided into sub-tasks
42

43. Example Hierarchical Task Analysis
0.
1.
2.
3.
4.
5.
In order to buy a DVD
locate DVD
add DVD to shopping basket
enter payment details
complete address
confirm order
plan 0:
If regular user do 1-2-5.
If new user do 1-2-3-4-5.
43

44. Example Hierarchical Task Analysis
(graphical)
44

45. Hierarchical Task Analysis (2)
• More in the tutorial
45