Transcript Interface Guidelines & Principles

Interface Guidelines & Principles
Focus on Users & Tasks
Not Technology
Interface Guidelines & Principles
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7 principles for Interface Design
1. Focus on the users & tasks, not technology.
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Easier said than done for programmers.
Interface Design vs. Development
 Design
– Somewhat, creative human activity for interface.
– Specifies interface’s appearance & interactions.
– Here is where we do mock ups, specs, etc.
 Development
– Interface production.
– Implementation of design.
– Here is where Java, C++, HTML, etc. come in
 HCC does both
How to focus on users & tasks?
 Must asks a few questions in the beginning.
Who
 For whom is this product or service being
designed?
 Who are the customers, users, experts, etc.
– Customers = Users = Experts ?
 What is the background of the users?
– education, culture, ethics, age, sex, etc.
What
 What is the product or service for?
– What problem does it solve?
– What value will it add?
 What activity is it intended to support?
– What are the skills/knowledge of the users?
– What are the motivations for users?
How
 How do the users work in the domain now?
– How will the product or service fit in or replace it?
 How do users conceptualize the tasks now?
– How will they conceptualize the tasks later?
User Centered Design
User Centered Design
 A way to force yourself to identify and
consider the relevant human factors in your
design
 Helps reduce the number of decisions made
out of the blue, and helps focus design
activities
 Helps document and defend decisions that
may be reviewed later
UCD - Know the Users
 Ask the Who questions
– Skills, background, etc.
 Know the user’s job
 Possible exception
– World Wide Web, who are your users?
UCD – Participatory Design
 Participatory Design
– The user takes a participatory role in the design
process.
 Involve the users as much as possible, but
don’t over do it.
– How many people does it take to screw in a
light bulb?
UCD – Design to Prevent Errors
 Common errors should be avoided.
– rm *.*, delete *.*
 Through experience, you will learn how to
spot vulnerable areas that are error prone.
– Much easier said than done!
UCD – Optimize User Operations
 Add shortcuts where necessary.
 CAUTION!!!
– Shortcuts can be over rated in some systems.
– Know your users first and then decide on shortcuts.
UCD – Keep Control with User
 The user should be in control or at least
think he/she is in control.
 Manage user interaction and control point of
view.
UCD – Help the User
 Provide assistance throughout your system.
 The user should be able to get help any time
he/she wishes (control point of view).
 Help is a difficult task because sometimes
users need help with the help.
User Centered Design
DESIGN
USE &
EVALUATE
IMPLEMENT
UCD: 9 Step Overview
1.
2.
3.
4.
5.
6.
7.
8.
9.
Define the Context
Describe the User
Task Analysis
Function Allocation
System Layout / Basic Design
Mockups & Prototypes
Pilot Test & Usability Testing
Iterative Test & Redesign
Updates & Maintenance
1. Define the Context
 Context:
– Life critical systems, applications
– Industrial, commercial, military, scientific,
consumer
– Office, home, entertainment
– Exploratory, creative, cooperative
 Market
 Customer (not the same as the User)
…Design Impacts?…
2. Describe the User (!!)
 Physical attributes
(age, gender, size, reach, visual angles, etc…)
 Physical work places
(table height, sound levels, lighting, software version…)
 Perceptual abilities
(hearing, vision, heat sensitivity…)
 Cognitive abilities
(memory span, reading level, musical training, math…)
 Personality and social traits
(likes, dislikes, preferences, patience…)
 Cultural and international diversity
(languages, dialog box flow, symbols…)
 Special populations, (dis)abilities
3. Task Analysis
 Talk to and observe users (NOT customers)
doing what they do
 List each and every TASK
 Break tasks down into STEPS
 ABSTRACT into standard tasks
(monitor, diagnose, predict, control, inspect, transmit,
receive, decide, calculate, store, choose, operate, etc.)
4. Function Allocation
 Consider the whole system!
 Decide who or what is best suited to perform
each task (or each step)
 Base this on knowledge of system
hardware, software, human users,
communications protocols, etc.
 Allocation constraints: Effectiveness;
Cognitive/affective; Cost; Mandatory
5. System Layout / Basic Design
 Summary of the components and their
basic design
 Cross-check with any Requirements
Documents; Human Factors refs; Hardware
specs; Budgets
 Ensure that the system will support the
design and comply with constraints
6. Mockups & Prototypes
 “Informed Brainstorming”
 RAPIDLY mock up the user interfaces for
testing with real people
 Pen and paper or whiteboard to start
 Iterate, iterate, iterate!!
 Increasingly functional & veridical
 List audio & visual details at same levels of
detail in the prototypes
7. Pilot Test & Usability Testing
 Pilot Test
– Small usability study before the real study.
– Pilot tests are conducted as a prelude to the real usability
test.
– Helps to refine the usability test process and procedures.
– Get preliminary results before the real test.
7. Pilot Test & Usability Testing
 Get real (or representative) users to do what they do,
using the prototypes
 Subjective and objective feedback. Sometimes users
“want” features that actually yield poor performance
 Video tape, lots of notes
 Feedback into the iterative evaluation & redesign of
the system
 “Discount” usability testing can be very effective,
using fewer subjects, more rapid results
8. Iterative Test & Redesign
 Repeat cycles of testing and reworking the
system, subject to cost/time constraints
 Focus on Functionality First !
 Plan for several versions during
development
9. Updates & Maintenance
 In-the-field feedback, telemetry, user data,
logs, surveys, etc.
 Analyze and make iterative redesign/test
recommendations
 Updates and maintenance plan as part of
the design!
UCD: 9 Step Overview
1.
2.
3.
4.
5.
6.
7.
8.
9.
Define the Context
Describe the User
Task Analysis
Function Allocation
System Layout / Basic Design
Mockups & Prototypes
Pilot Tests & Usability Testing
Iterative Test & Redesign
Updates & Maintenance
UCD: Focusing Your Efforts
 There are real-world constraints
 Cutting out steps is not the way to
economize!
 Optimize the efficiency of each step
 Here: Focus on the context and the user, to
get the most value for the time spent
Concepts, Principles, Guidelines
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No “cookbooks” (sorry!)
No simple, universal checklists
Think from perspective of user
There are many concepts, principles, and
guidelines to help you
 Focus on higher level principles that apply
across situations, display types, etc.
Summary
 Humans will use your system
 Considering their many attributes, abilities, and
limitations will lead to a better design
 It’s not just common sense!
 Human Factors is the study of how our “human
factors” affect design
 User Centered Design is a philosophy and a
process to help designers sort it all out
 It matters! And it ain’t easy!
 Practice makes better (never perfect!)