Intro to Human Factors

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Intro to Human Factors User-Centered Design

• Bruce Walker
• Georgia Institute of Technology
• bruce.walker_at_psych.gatech.edu

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Good Design (our goal!)

• Every designer wants to build a high-quality
  interactive system that is admired by colleagues,
  celebrated by users, circulated widely, and
  imitated frequently. (Shneiderman, 1992, p.7)
• and anything goes!

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The Good
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The Good
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The Bad
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The Bad
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The Bad
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The Ugly
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The Ugly
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The (really) Ugly
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What The???
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But What Makes it Good?!

• Functionality
• Speed efficiency
• Reliability, security, data integrity
• Standardization, consistency
• USABILITY !

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Closer to Fine A Philosophy

• The human user of any system is the focus of the
  design process. Planning and implementation is
  done with the user in mind, and the system is
  made to fit the user, not the other way around.

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What Human Factors Is

• Systems are built for humans must be designed
  for the user
• Recognize individual differences appreciate
  design implications of these factors
• Recognize the design of things, procedures, etc.,
  influences human behavior and well-being
• Emphasize empirical data evaluation
• Rely on the scientific method
• Things, procedures, environments, and people do
  not exist in isolation

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What HF Is Not

• NOT just applying checklists and guidelines
• These can help, but USD is a whole philosophy
• NOT using oneself as the model user
• Know your real users recognize variation in
  humans
• NOT just common sense
• Knowing how to design a fire alarm so it will be
  heard over background noise is not something we
  all know.
• The HF specialist knows where or how to get the
  information needed to answer design questions

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HF Evolution in America

• Taylor (1911) Scientific managementBethlehem
  Steel time motion study
• Gilbreth (1909) Work physiologyBricklaying,
  surgery
• Alfred Binet (1905) Testing
• Paul Fitts (1945)Engineering psychologyAviation
  , military systems
• Computers, complex systems,telecom, consumer
  products

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HFES Professional Props

• Human Factors Ergonomics Society(www.hfes.org)
• International Ergonomics Association(www.iea.cc)
• ACM SIGCHI(www.acm.org/sigchi)
• IEEEs Systems, Man, Cybernetics
  Society(www.isye.gatech.edu/ieee-smc)

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What Are the Key Factors?!

• It Depends
• Physical factors
• Perceptual factors
• Cognitive factors
• Social factors
• Historical factors
• they ALL can affect design!

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User Centered Design

• A way to force yourself to identify and consider
  the 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

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The Tao of UCD
DESIGN
IMPLEMENT
USE EVALUATE
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UCD 9 Step Overview

• Define the Context
• Describe the User
• Task Analysis
• Function Allocation
• System Layout / Basic Design
• Mockups Prototypes
• Usability Testing
• Iterative Test Redesign
• Updates Maintenance

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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?

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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

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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.)

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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

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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

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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

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7. 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

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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

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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!

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UCD 9 Step Overview

• Define the Context
• Describe the User
• Task Analysis
• Function Allocation
• System Layout / Basic Design
• Mockups Prototypes
• Usability Testing
• Iterative Test Redesign
• Updates Maintenance

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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

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Concepts, Principles, Guidelines

• 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.
• Details next time!

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Summary

• Humans will use your system
• Considering their many attributes, abilities, and
  limitations will lead to a better design
• Its 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 aint easy!
• Practice makes better (never perfect!)

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Design Assignment Background

• Design the CONTROLS or the DISPLAYS for a
  1-person research submersible.
• Used in thermal vent research, 1000 meter depths,
  by a variety of oceanographers, biologists,
  geophysicists, etc.
• 8 hr missions, variable scientific component
• User must control the vessel, as well as do the
  science, while monitoring the sub and
  communicating with the surface
• http//www.submersiblesubmarines.com

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Design Gallery

• http//www.submersiblesubmarines.com

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Design Gallery

• http//www.submersiblesubmarines.com

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Design Assignment Stages

• Choose
• Input Controls or Output Displays
• Complete UCD Worksheets
• Focus on Context User, this time
• Note Explicitly state design implications !
• Brief Task Analysis Function Allocation
• Systems Layout / Basic Design
• Avoid colors, details, asthetic elements unless
  functionally relevant
• Mention any assumptions about the other half
  (input or output), but only briefly

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Assignment, continued

• Usability Testing
• 2 participants, not from class
• Wizard of Oz style
• Observe Take Notes (switch roles)
• Document Results, and Recommendations for
  Redesign
• Version 0.2 (iterate on design)

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Deliverables (per team)

• Completed UCD Worksheets
• emphasis on Context User
• Version 0.1 sketches, etc. scan to PDF
• Notes Comments from Usability Test
• Version 0.2
• Narrative describing the changes, and how they
  came out of the UCD process
• EMAIL PDF File tobruce.walker_at_psych.gatech.eduD
  eadline NOON, September 28, 2001

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Thank you!

• and good luck!
• See you in two weeks!