|
|||||
Human
Computer Interaction
(CS408)
VU
Lecture
23
Lecture
23. Requirements
Learning
Goals
As the
aim of this lecture is to
introduce you the study of
Human Computer
Interaction,
so that after studying this
you will be able to:
· Understand
the narratives and
scenarios
· Define
requirements using persona-based
design
It has
already been discussed how to
capture qualitative information
about users.
Through
careful analysis of this
information and synthesis of user
models, we can get
a clear
picture of our users and
their respective goals. It
has also been explained
how
to
prioritize which users are
the most appropriate design targets.
The missing piece to
the
puzzle, then, is the process
of translating this knowledge
into coherent design
solutions
that meet the needs of users
while simultaneously addressing business
needs
and
technical constraints.
Now we
shall describe a process for
bridging the research-design gap. It
employs
personas
as the main characters in
set of techniques that
rapidly arrive at
design
solutions
in an iterative repeatable, and
testable fashion. This
process has three
major
milestones:
defining user requirements;
using these requirements to in
turn define the
fundamental
interaction framework for
the product; and filling in
the framework with
ever-increasing
amounts of design detail.
The glue that holds
the process together
is
narrative:
use of personas to tell stories
that point to design.
Narrative as a
design tool
23.1
Narrative,
or storytelling, is one of the
oldest human activities.
Much has been written
about
the power of narrative to
communicate ideas. However, narrative
can also,
through
its efficacy at engaging and
stimulating creative visualization
skills, serve as
a
powerful tool in generating
and validating design ideas.
Because interaction
design
is first
and foremost the design of
behavior that occurs over
time, a narrative
structure,
combined
with the support of minimal
visualization tools such as
the whiteboard, is
perfectly
suited for envisioning and
representing interaction concept.
Detailed
refinement
calls for more sophisticated
visual and interactive
tools, but the
initial
work of
defining requirements and
frameworks is best done
fluidly and flexibly,
with
minimal
reliance on technologies that will
inevitably impede
ideation.
Scenarios
in design
Scenario
is a term familiar to usability
professional, commonly used to describe
a
method of
design problem solving by
concretization: making use of a
specific story to
both
construct and illustrate
design solutions. Scenarios are
anchored in the concrete,
but
permit fluidity; any member
of the design team can
modify them at will.
As
Carroll
states in his book, Making
Use:
Scenarios
are paradoxically concrete
but rough, tangible but
flexible ... they
implicitly
encourage `what-if'? Thinking among
all parties. They permit
the
articulation
of design possibilities without
understanding innovation ....
211
Human
Computer Interaction
(CS408)
VU
Scenarios
compel attention to the use
that will be made of the design
product.
They
can describe situations at many
levels of detail, for many
different
purposes,
helping to coordinate various
aspects of the design
project.
Carroll's
use of scenario-based design focuses on
describing how users
accomplish
tasks. It
consists of an environment setting
and includes agents or
actors that are
abstracted
stand-ins for users, with
role-based names such as
Accountant or
Programmer.
Although
Carroll certainly understands the
power and importance of
scenarios in the
design
process, there can be two
problems with scenarios as Carroll
approaches them:
· Carroll's
scenarios are not concrete
enough in their representation of
the
human
actor. It is impossible to design
appropriate behaviors for a
system
without
understanding in specific detail
the users of the system.
Abstracted,
role-oriented
models are not sufficient concrete to
provide understanding or
empathy
with users.
· Carroll's
scenarios jump too quickly
to the elaboration of tasks
without
considering
the user's goals and
motivations that drive and
filter these tasks.
Although
Carroll does briefly discuss
goals, he refers only to
goals of the
scenario.
These goals are somewhat
circularly defined as the
completion of
specific
tasks. Carroll's scenarios
begin at the wrong level of
detail: User
goals
need to be considered before user
tasks can be identified and
prioritized.
Without
addressing human goals, high-level
product definition
becomes
difficult.
The
missing ingredient in scenario-based methods is
the use of personas. A
persona
provides
a sufficiently tangible representation of
the user to act as a believable
agent
in the
setting of a scenario. This enhances
the designer's ability to
empathize with
user
mental models and perspectives. At
the same time, it permits an
exploration of
how
user motivations inflect and
prioritize tasks. Because
personas model goals
and
not
simply tasks, the scope of
the problem that scenarios
address can also be
broadened
to include product definition.
They help answer the
questions, " what
should
this product be?" and
"how should this product
look and behave?"
Using
personas in scenarios
Persona-based
scenarios are concise narrative
descriptions of one or more
personas
using a
product to achieve specific
goals. Scenarios capture the
non-verbal dialogue
between
artifact and user over
time, as well as the
structure and behavior
of
interactive
functions. Goals serve as
filter for tasks and as
guides for structuring
the
display
of information and controls
during the interactive
process of constructing
the
scenarios.
Scenario
content and context are
derived from information
gathered during the
Research
phase and analyzed during
the modeling phase. Designers
role-play
personas
as the characters in these scenarios,
similar to actors
performing
improvisation.
This process leads to real-time synthesis
of structure and
behavior--
typically,
at a whiteboard--and later informs
the detailed look and
feel. Finally,
personas
and scenarios are used to
test the validity of design
ideas and assumptions
throughout
the process. Three types of
persona-based scenarios are employed
at
different
points in the process, each
time with a successively narrower
focus.
212
Human
Computer Interaction
(CS408)
VU
Persona-based
scenarios versus use
cases
Scenarios
and use cases are both
methods of describing a digital system.
However,
they
serve very different functions.
Goal-directed scenarios are an iterative
means of
defining
the behavior of a product
from the standpoint of
specific users. This
includes
not
only the functionality of
the system, but the
priority of functions and
the way
those
functions are expressed in terms of what
the user sees and
how he interacts with
the
system.
Use
cases, on the other hand,
are a technique that has been
adopted from software
engineering
by some usability professionals.
They are usually exhaustive
description f
functional
requirements of the system,
often of a transactional nature,
focusing on
low-level
user action and system
responds--is not, typically,
part of conventional or
concrete
use case, many assumptions
about the form and
behavior of the system to
be
designed
remain implicit. Use cases
permit a complete cataloguing of
user tasks for
different
classes of users, but say
little or nothing about how
these tasks are
presented
to the
user or how they should be
prioritized in the interface. Use
cases may be useful
in
identifying edge cases and
for determining that a
product is functionally
complete,
but
they should be deployed only
in the later stages of
design validation.
Envisioning
solutions with persona-based
design
23.2
It has
already been discussed that
the translation from robust
models to design
solutions
really consists of two major
phases. Requirements Definition
answers the
broad
questions about what a
product is and what it
should do, and
Framework
Definition
answers questions about how
a product behaves and how it is
structured to
meet user
goals. Now we look
Requirement Definition phase in
detail.
Defining
the requirements
The
Requirement Definition phase
determines the what of the
design: what
functions
our
personas need to use and
what kind of information
they must access to
accomplish
their
goals. The following five
steps comprise this
process:
1.
Creating problem and vision
statement
2.
Brainstorming
3.
Identifying persona expectations
4.
Constructing the context
scenario
5.
Identifying needs
Although
these steps proceed in
roughly chronological order,
they represent an
iterative
process. Designers can expect to
cycle through step 3 through
5 several times
until
the requirements are stable.
This is a necessary part of
the process and
shouldn't
be
short-circuited. A detailed description
of each of these steps
follows.
Step1:
Creating problem and vision
statement
Before
beginning any process of
ideation, it's important for
designers to have a clear
mandate
for moving forward, even if
it is a rather high-level mandate.
Problem and
vision
statements provide just such
a mandate and are extremely
helpful in building
consensus
among stakeholders before
the design process moves
forward.
At a high
level, the problem statement
defines the objective of the
design. A design
problem
statement should concisely reflect a
situation that needs
changing, for both
213
Human
Computer Interaction
(CS408)
VU
the
personas and for the
business providing the
product to the personas.
Often a
cause-and-effect
relationship exists between
business concerns and persona
concerns.
For
example:
Company
X's customer satisfaction ratings are low
and market share
has
diminished
by 10% over the past
year because users don't
have adequate tools
to
perform X, Y and Z tasks
that would help them meet
their goal of G.
The
connection of business issues to
usability issues is critical to
drive stakeholders'
buy-in to
design efforts and to frame
the design effort in term of
both user and
business
goals.
The
vision statement is an inversion of the
problem statement that serves as a
high-
level
design vision or mandate. In
the vision statement, you
lead with the
user's
needs,
and you transition from
those to how business goals
are met by the
design
vision:
The
new design of Product X will
help users achieve G by
giving them the
ability
to perform X, Y and Z with
greater [accuracy, efficiency,
and so on],
and
without problems A, B, C that
they currently experience.
This will
dramatically
improve Company X's customer satisfaction
ratings and leads to
increased
market share.
The
content of both the problem
and vision statement should come
directly from
research
and user models. User
goals and needs should
derive from the primary
and
secondary
personas, and business goals
should be extracted from
stakeholder
interviews.
Step 2:
Brainstorming
Brainstorming
performed at this earlier
stage of Requirements Definition
assumes a
somewhat
ironic purpose. As designers, you may
have been researching and
modeling
users
and the domain for days or
even weeks. It is almost
impossible that you
have
not
had design ideas percolating in
your head. Thus, the
reason we brainstorming at
this
point in the process is t
get these ideas out our
heads so we can "let them
go" at
least for
the time being. This
serves a primary purpose of
eliminating as much
designer
bias as possible before
launching into scenarios, preparing
the designers to
take on
the roles of the primary
personas during the scenario
process.
Brainstorming
should be unconstrained and
critical--put all the wacky
ideas you've
been
considering (plus some you
haven't) out n the table
and be the prepared
to
record
them and file them
away for safekeeping until
much later in the process.
It's
not
likely any of them will be
useful in the end, but
there might be the germ
of
something
wonderful that will fit into
the design framework you
later create.
Holtzblatt
& Beyer describe a facilitated method
for brainstorming that can
be useful
for
getting a brainstorming session started,
especially if your team includes
non-
designers.
Step 3:
Identifying persona
expectations
The
expectations that your persona
has for a product and
its context of use
is,
collectively,
that persona's mental model
of the product. It is important
that the
representation
model of the interface--how
the design behaves and
presents itself--
should
match the user's mental
model as closely as possible,
rather than reflecting
the
implementation
model of how the product is
actually constructed
internally.
For
each primary persona you must
identify:
214
Human
Computer Interaction
(CS408)
VU
General
expectations and desires
each may have about
the experience of
using
·
the
product
Behaviors
each will expect or desire from
the product
·
Attitude,
past experience, aspirations
and other social, cultural,
environmental
·
and
cognitive factors that
influence these
desires
Your
persona descriptions may contain
enough information to answer some of
these
questions
directly; however, you
should return to your
research data to analyze
the
language
and grammar of how user
subjects and describe objects and
actions that are
part of
their usage patterns.
Some
things to look for
include:
· What
do the subjects mention
first?
· Which
action words (verbs) do they
use?
· Which
intermediate steps, tasks, or
objects in a process don't
they mention?
After
you have compiled a good
list of expectations and
influences, do the same
for
secondary
and customer personas and
crosscheck similarities and
differences.
Step 4:
constructing context
scenarios
Scenarios
are stories about people and
their activities. Context
scenarios are, in fact,
the most
story-like of the three
types of scenario we employ in that
the focus is very
much on
the persona, her mental
models, goals, and
activities. Context
scenarios
describe
the broad context in which
usage patterns are exhibited
and include
environmental
and organizational considerations.
Context scenarios establish
the
primary
touch-points that each
primary and secondary persona has
with the system
over
the course of a day, o some
other meaningful length of
time that illuminates
modes of
frequent and regular use.
Context scenarios are sometimes, for
this reason,
called
day-in-the-life scenarios.
Context
scenarios address questions
such as the following
What is
the setting in which the
product will be used?
·
Will it
be used for extended amounts or
time?
·
Is the
persona frequently interrupted?
·
Are
there multiple users on a
single workstation/device?
·
What
other products is it used
with?
·
How
much complexity is permissible,
based on persona skill and
frequency of
·
use?
What
primary activities does the
persona need to accomplish to meet
her
·
goals?
What is
the expected end result of
using the product?
·
To ensure
effective context scenarios, keep
them broad and relatively
shallow in
scope.
Resist the urge of dive
immediately into interaction
detail. It is important to
map
out the pig picture
first and systematically
identify needs. Doing this
and using
the
steps that follow prevent
you from getting lost in
design details that may
not fit
together
coherently later.
215
Human
Computer Interaction
(CS408)
VU
Context
scenarios should not represent
system behaviors as they
currently are. These
scenarios represent
the brave new world of
goal-directed products, so,
especially in
the
initial phases, focus on the
goals. Don't yet worry
about exactly how things
will
get
accomplished--you can initially
treat the design as a bit of
a magic black box.
Sometimes
more than one context
scenario is necessary. This is true
especially when
there are
multiple primary personas,
but sometimes even a single
primary persona
may
have two or more distinct
contexts of use.
An
example text scenario
The
following is an example of a first
iteration of a context scenario for a
primary
persona
for a PDA/phone convergence
device and service; Salman,
a real-estate agent
in
Lahore. Salman's goals are
to balance work and home
life, cinch the deal,
and
make
each client feel like he is
his only client.
Salman's
context scenario might be as
follow:
1.
Getting ready in the
morning, Salman uses his
phone to check e-mail. It
has a
large
enough screen and quick
connection time so that it's
more convenient
than
booting up a computer as he rushes to
make his daughter, Alia,
a
sandwich
for school.
2. Salman
sees e-mail from his newest
client who wants to see
a house this
afternoon.
Salman entered his contact
info a few days ago, so now
he can call
him
with a simple action right
from the e-mail.
3. While
on the phone with his
client, Salman switches to speakerphone
so he
can
look at the screen while
talking. He looks at his
appointments to see
when
he's
free. When he creates a new
appointment, the phone
automatically makes
it an
appointment with client,
because it knows with whom
he is talking. He
4.
quickly keys the address of
the property into the
appointment as he finishes
his
conversation.
5. After
sending Alia off to school,
Salman heads into the
real-estate office to
gather
the papers he needs for
the plumber working on
another property. His
phone
has already updated his
Outlook appointments so the
rest of the office
knows
where he'll be in the
afternoon.
6. The
day goes by quickly, and
he's running a bit late. As
he heads towards the
property
he'll be showing client, the
phone alerts him that
his appointment is
in 15
minutes. When he flips open
the phone, it shows not
only the
appointment,
but a list of all documents
related to client, including
e-mail,
memos,
phone messages, call logs to
client's number, and even
thumbnail
pictures
of the property that Salman
sent as e-mail attachments.
Salman
presses
the call button, and
the phone automatically connects to
client because
it knows
his appointment with him is
soon. He lets him know he'll
be there in
20
minutes.
7. Salman
knows the address of the
property, but is a bit unsure
exactly where it
is. He
pulls over and taps
the address he put into
the appointment. The
phone
downloads
directions along with a
thumbnail map showing his
location
relative
to the destination.
8. Salman
gets to the property on time
and starts showing it to
client. He hears
the
phone ring from his
pocket. Normally while he is in an
appointment, the
phone
will automatically transfer directly to
voicemail, but Alia has a
code she
can
press to get through. The
phone knows it's Alia
calling, and uses a
distinctive
ring tone.
216
Human
Computer Interaction
(CS408)
VU
9. Salman
takes the call--Alia missed
the bus and needs a
pickup. Salman calls
her
daughter and ask her
that he will pick her up
after 30 minutes.
Now
how the scenario remains at
a fairly high level, not
getting into too
specific
about
interface or technologies. It's
important to create scenarios
that are within the
realm of
technical possibility, but at
this stage the details of
reality aren't yet
important.
Step 5:
identifying needs
After
you are satisfied with an
initial draft of your
context scenario, you can
begin to
analyze
it to extract the persona'
needs. These needs consist of
objects and actions
as
well as
contexts. It is preferred not to
think of needs as identical to
tasks. The
implication
is that tasks must be manually
performed by the user, whereas
the term
needs
implies simply that certain
objects need to exist and
that certain actions on
them
need to
happen in certain contexts.
Thus, a need from the scenario
above might be:
Call
(action) a person (object) directly
from an appointment
(context)
If you
are comfortable extracting needs in
this format, it works quite
well; you can
separate
them as described in the
following sections.
Data
needs
Persons'
data needs are the
objects and information that
must be represented in the
system.
Charts, graphs, status markers,
document types, attributes to be
sorted,
filtered,
or manipulated, and graphical
object types to be directly
manipulated are
examples
of data needs.
Functional
needs
Functional
needs are the operations
that need to be performed on the
objects of the
system
and which are eventually
translated into interface
controls. Functional
needs
also
define places or containers
where objects or information in
the interface must be
displayed.
Contextual
needs and
requirements
Contextual
needs describes relationships
between sets of objects or
sets of controls, as
well as
possible relationship between
objects and controls. This
can include which
types of
objects to display together to
make sense for workflow or
to meet specific
persona
goals, as well as how
certain objects must interact
with other objects and
the
skills
and capabilities of the
personas using the
product.
Other
requirements
It's
important to get a firm idea
of the realistic requirements of
the business and
technology
you are designing.
· Business
requirements can include
development timelines, regulations,
pricing
structures,
and business models.
· Technical
requirements an include weight, size,
form-factor, display,
power
constraints,
and software platform
choices.
· Customer
and partner requirements can
include ease of
installation,
maintenance,
configuration, support costs,
and licensing agreements.
Now
design team should have a mandate in
the form of the problem
and vision
statements, a
rough, creative overview of
how the product is going to
address user
217
Human
Computer Interaction
(CS408)
VU
goals in
the form of context scenarios,
and a reductive list of
needs and
requirements
extracted
from your research user
models, and scenarios. Now
you are ready to
delve
deeper
into the details of your
product's behaviors, and
begin to consider how
the
product
and its functions will be
represented.
218
Table of Contents:
|
|||||