Transcript Document

Chapter 6
The Process of Interaction Design
By:





Matt Bergstein
Kevin Clark
Carol Lawson
Angelo Mitsopoulos
Phil Townsend
Introduction
Intent of design is to develop a product that helps its users achieve
their goals
How can we do this?

CH 1 expressed the importance of designing products which aid in
everyday tasks
Begin by understanding the product (who needs it, how they will use
it, where they will
use it)
How do we gain this knowledge?

Involving the user throughout the process of design
But what about innovative products where the user is less likely to
envision its possibilities?
Goals of this Chapter
Consider what ‘doing’ interaction design involves
Ask and provide answers for some important questions
about the interaction design process
Introduce the idea of a lifecycle model to represent a set
of activities and how they are related
Describe some lifecycle models from software
engineering and HCI and discuss how they relate to the
process of interaction design
Present a lifecycle model of interaction design
What is Interaction Design About?
Fields of design



Graphic design
Architectural design
Industrial and Software design
Each has its own interpretation
Oxford’s Def: “(design is) a plan or scheme conceived in
the mind and intended for subsequent execution.”
Designing therefore involves the development of such a
plan or scheme, and for it to execute, it has to be
informed with knowledge about its use and the target
domain. (Ex: multi-level roads)
Interaction Design
User-centered approach (users’ concerns direct
development)
Trade-offs and balancing (Ex: Road)
Evaluation and alternate solutions
Marc Rettig “To get a good idea, get lots of
ideas”
Brainstorming stimulates innovation
Communicating Interaction Design
Communication is key
Must express clearly to allow review,
revision, and improvement
Ways to communicate:



Series of sketches (building plans)
Description in natural language
Building prototypes
Four Basic Activities of Interaction Design (Intro)
Identifying Needs and Establishing Requirements

Who target users are and what are their needs
Developing Alternative Designs


Conceptual Design – creating a conceptual model of what the
product does
Physical Design – detail of the product (color, sound, images,
menus)
Building Interactive Versions of the Designs

Allows user to actually interact (not specifically software vers)
Ex: Paper-based (cheap, easy)
Evaluating Designs

Determining usability and acceptability
Three Characteristics of Interaction Design
Process
User Focus


Center of attention in book’s entirety
Center of Interaction Design Process
Specific Usability Criteria


Specific usability and user experience goals set at beginning of
project
Help designers choose between alternative designs and check
projects progress as developed
Interaction


Allows designs to be refined based on feedback
Takes time and must be repeated several times
Practical Issues
Questions to be answered before interaction
design:

Who are the users?

What do we mean by needs?

How do you generate alternative designs?

How do you choose among alternatives?
Who Are The users?
We need to find out the user’s requirements and needs
Identifying users:


User – the people who interact directly with the product to
achieve a task
Others?
Those who manage direct users, those who receive products from
the system, those who test the system, those who make purchasing
decisions, and those who use competitive products. (Holtzblatt and
Jones 1993)
Categories of user (Eason 1987):



Primary – hands-on users of the system
Secondary – occasional users
Tertiary – those affected by system or influence its purchase.
Who Are The Users?
Stakeholders – wide collection of people who all have a
stake in the development of a successful product
Includes:




Development team and their managers
Direct users and their managers
Recipients of the product’s output
People who may lose their jobs because of the introduction of the
new product
Conclusion:



Very wide range
Don’t include all of them
Be aware of who you’re affecting
What Do We Mean By “Needs”?
Not just “what do you need”?
Approach:




Characteristics and capabilities of users
What they are trying to achieve
How they currently achieve it
Would they achieve goals more effectively if supported different
Target group must be consulted, not what you would like
New innovations require cultural change in target
population
How Do You Generate Alternative Designs?
Common human tendency is to stick with something that
we know works
We end up overlooking good alternatives, which is a
crucial step in the design process
Where do alternative ideas come from?



Cross-fertilization of ideas from different applications
Evolution of an existing product through use and observation
Straightforward copying of other, similar products
Therefore, it helps to deliberately seek out suitable
sources of inspiration
Design Process
Under some circumstances, the scope to consider
alternative designs may be limited
Design is a process of:



balancing constraints
constantly trading off one set of requirements with another
drawing on the designers own experiences
The constraints may be such that there are very few
viable alternatives available
Upgrades to an existing system may or may not keep
familiar elements
Design Examples:
If designing a software system to run under the Windows operating
system, then elements of the design will be prescribed because you
must conform to the Windows “look and feel” and to other
constraints intended to make Windows programs consistent for the
user
When designing the Windows 95 operating system to replace the
Windows 3.1 and Windows for Workgroups 3.11 operating systems,
the designers initially focused too much on consistency with the
earlier versions (keeping familiar elements)
For designing an electronic calendar, although many software-based
applications already existed, paper-based books were a good
source of inspiration (for the author of our text)
IDEO - A Box Full of Ideas
IDEO, an international, innovative product design company, which has been
involved in the development of many artifacts including the first commercial
computer mouse and the PalmPilot V
Uses a TechBox, which holds around 200 gizmos and interesting materials
which are cataloged with more detailed information available via the
TechBox’s online catalog
Staff at IDEO take along a selection of items from the box to brainstorming
meetings to be used as visual props or possible solutions to a particular
issue
When items become common place, they are removed from the TechBox to
make way for the next generation of fascinating contraptions
http://ideo.com
Copying for Inspiration: Is It Legal?
Copyright:


covers the expression of an idea and not the idea itself
is free and is automatically invested in the author of something, e.g., the writer of
a book or a programmer who develops a program, unless they sign the copyright
over to someone else
Patents:




does protect the idea rather than just the expression of the idea
there are various forms, each of which is designed to allow the inventor the
chance to capitalize on the idea
unusual for software to be patented, since it is a long, slow and expensive
process
recent trend, however, towards patenting business processes (Amazon has
patented its “one-click” purchasing process)
The dilemma comes in knowing when it’s OK to use someone else’s work
as a source of inspiration and when you are infringing copyright or patent
law
http://www.loc.gov/copyright/
http://www.uspto.gov/
How Do You Choose Among
Alterative Designs?
Choosing among alternatives is about making decisions
These decision are made by:


Information gathered about users and their tasks
The technical feasibility of the idea
Fall into two categories:


Those about externally visible and measurable features
Those about internal characteristics to the system
Examples?
Why We Concentrate On The
External Factors?
Our driving force is the way in which users
interact with the product
Therefore, we focus on visible and measurable
behavior that affect this interaction
Internal workings are important only to the extent
to which they affect the external behavior


The tasks that the user will perform should determine
the design
Technical issues should take care of themselves
Choosing Between Alternatives –
The User-centered Approach
Let users and stakeholders interact with the
product

Discuss their experiences, preference, and
suggestions
This process requires that:


The designs are readily available that is reasonable
evaluated by users
The process is free from technical jargon and
complicated notations
Choosing Between Alternatives –
Documentation
Uses a description of how something will
work or a diagram showing its components
Downsides to this approach:


Uses a static depiction for dynamic behavior
Doesn’t communicate what the product will
actually be like to the users
Choosing Between Alternatives –
Prototyping
Involves producing a limited version of the product in
order to answer specific questions about the design and
feasibility
Used to overcome potential client misunderstandings
and to test the technical feasibility of a suggested design
and production
Gives a better impression of the user interface than
explanations
There are various types of prototyping suitable
depending on the stage of development and types of
information needed
Choosing Between Alternatives –
Quality
Make a decision based on a perceived level of “quality”
This process requires a clear understanding of what is
meant by “quality”
Downsides to this approach:




People have different definitions of what quality is
People have different expectations for quality
Many projects have different stakeholder group, each who can
define quality of a different way
A clear, concise definition of quality is rarely properly
documented
Usability Engineering
The process of writing down formal, verifiable – and
hence measurable – usability criteria is a key
characteristic of an approach to interaction design called
usability engineering
This involves specifying quantifiable measures of
product performance, documenting them in a usability
specification, and assessing the product against them
Example:

This can be used to make changes to a previous version of a
system based on feedback from results of usability tests
Lifecycle Models: Showing How
The Activities Are Related
A lifecycle model is used to capture a set of
activities and how they are related

More sophisticated models also incorporate a
description when and how to move from one activity
to the next
They are popular because they allow for an
overall view of the development effort so that
progress can be tracked, deliverables specified,
resources allocated, and targets set
Lifecycle Models cont’d
No matter how complex, any lifecycle model is a
simplified version of reality
It is an abstraction that only includes that
amount of detail needed for the task at hand

Additional details will be needed to actually put a
lifecycle model into practice
Many different types of these models are
available

Some based on the software engineering and HCI
models
A Simple Lifecycle Model For
Interaction Design
Please refer to the model on page 186 in Figure 6.7
This model incorporates iteration and encourages a user
focus
This model is not intended to be prescriptive
It includes the following steps:






Start with identifying needs and requirements
Alternative designs are generated based on the requirements
Interactive versions of the designs are developed and evaluated
The team gets feedback and determines whether or not to
continue or iterate back
The final product will emerge in an evolutionary fashion
This process may vary from product to product
Lifecycle Models In Software Engineering
Before the waterfall method was proposed in 1970, there
was no agreed upon approach to software development.
Since, many lifecycle models have come about:
 The waterfall
 The Spiral
 Rapid Applications Development (RAD)
These were chosen to be discussed because they
represent models used successfully in industry and they
show how the emphasis in software development has
gradually changed to include a more iterative, usercentered view.
The Waterfall Lifecycle Model
First Known Model
Linear Model
 Each step must be
completed before
moving on next step
Some feedback shown to
be useful, but idea of
iteration was not
embedded in the model
and the opportunity to
review and evaluate with
users was not built into
this model.
Spiral Lifecycle Model
Suggested by Barry Boehm, 1988
Two main features:


Risk Analysis
Prototyping
Incorporates them in an iterative framework so
that ideas and progress are repeatedly checked
and evaluated.
Explicitly encourages alternatives to be
considered.
Identifies and controls risk.
Spiral Lifecycle Model
Rapid Applications Development
User-centered
Minimized risk caused by requirement changing
during the course of the project
Two key features:


Time-boxing: Time-limited cycles of approximately six
months, at the end of which a system or partial
system must be delivered.
JAD Workshops: (Joint Application Development)
workshops where users and developers come
together to thrash out the requirements of the system.
Rapid Applications Development
Popularity of RADs has
led to industry standard
method called DSDM.
Five phases to DSDM:
Feasibility Study,
Business study, functional
model iteration, design
and build iteration, and
implementation.
Rapid Applications Development
No order of activities.
Activities are highly interconnected.
Evaluation is central to model.
Usability Engineering Lifecycle
Provides a holistic view of usability engineering and a
detailed description of how to perform usability tasks
Three tasks involved:
 Requirements Analysis
 Design/Testing/Development
 Installation
Includes the style guide as a mechanism for capturing
and disseminating the usability goals of the project