Usability Goal Setting

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Usability Goal Setting
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How do we know weve succeeded?How do we
measure success?
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Usability Goal Setting

• Part of the Usability Engineering process
• Set by the design team on basis of selected
  usability criteria
• E.g. user satisfaction, user preference, ease of
  use (efficiency), learnability, memorability
• Includes all project stakeholders should
  participate

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Where in the Lifecycle?

• After User Analysis and User Profile
• After Contextual Task Analysis
• Feeds into user interface design tasks

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Phase 1
REQUIREMENTS ANALYSIS
User Profile Contextual Task Analysis Platform
Capabilities Constraints General Design
Principles
Usability Goals
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Purpose

• Help to focus and drive the design process
  (early)
•  
• Serve as acceptance criteria during usability
  evaluation testing (later in process).

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• On the cold morning of December 17, 1903, the
  Wrights' contraption chugged into a
  27-mile-per-hour headwind and lifted itself a few
  feet off the ground. Orville, who was at the
  flyer's simple controls, hadn't learned how to
  handle the machine yet, and he kept it aloft only
  12 seconds. The craft flew just 120 feet but
  soared into the history books. In those few
  seconds, the 19th century and its wind- and
  steam-powered surface transportation separated
  and fell away from the 20th century.

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• On the cold morning of December 17, 1903, the
  Wrights' contraption chugged into a
  27-mile-per-hour headwind and lifted itself a few
  feet off the ground. Orville, who was at the
  flyer's simple controls, hadn't learned how to
  handle the machine yet, and he kept it aloft only
  12 seconds. The craft flew just 120 feet but
  soared into the history books. In those few
  seconds, the 19th century and its wind- and
  steam-powered surface transportation separated
  and fell away from the 20th century.

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Scope of Usability Goals

• Project dependent
• Team must decide on appropriate scope
• New product?
• Next version?

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We need it flawless by the beginning of October.
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Usability GoalsA Benchmark

• What do Usability Goals do for us?
• Make priorities explicit and visible
• Innovate for better usability
• Provide basis for tradeoff decisions
• Focus attention and resources
• Useful in design walkthroughs and throughout the
  entire product lifecycle

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• The X PRIZE is a 10,000,000 prize to jumpstart
  the space tourism industry through competition
  between the most talented entrepreneurs and
  rocket experts in the world. The 10 Million cash
  prize will be awarded to the first team that
• Privately finances, builds launches a
  spaceship, able to carry three people to 100
  kilometers (62.5 miles)
• Returns safely to Earth
• Repeats the launch with the same ship within 2
  weeks

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• The Ansari X PRIZE was modeled after the Orteig
  Prize, won by Charles Lindbergh in 1927 for being
  the first to fly non-stop from New York to Paris,
  and mirrors the hundreds of aviation incentive
  prizes offered early in the 20th Century that
  helped create today's 300 billion commercial
  aviation industry.
• On October 4, 2004, the X PRIZE Foundation
  captured the world's attention when we awarded
  the largest prize in history, the 10 million
  Ansari X PRIZE, to Mojave Aerospace Ventures for
  the flight of SpaceShipOne.
• To win the prize, famed aerospace designer Burt
  Rutan and financier Paul Allen led the first
  private team to build and launch a spacecraft
  capable of carrying three people to 100
  kilometers above the earth's surface, twice
  within two weeks.
• Ten times the amount of the prize purse was spent
  by the competitors trying to win the prize. The
  Ansari X PRIZE changed the way the public
  perceives spaceflight. The revolutionary
  surpassed our highest expectations, creating
  significant developments in the personal
  spaceflight industry even before the Ansari X
  PRIZE was awarded.

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More X Prizes

• Genomics
• 10M to the First Team to Sequence
• 100 Human Genomes in 10 Days
• In the worksan automotive X-prize

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high level visionthe problems that need to be
solved

• Because today's oil consumption is not
  sustainable - our current use of oil endangers
  our health, our economy, and the political and
  social stability of the world.
• Because 40 of world oil output fuels the
  automotive industry - and, in the U.S., 65 of
  oil consumption is in the transportation sector.
• Because automotive emissions contribute
  significantly to global climate change.
• Because there are no mainstream consumer
  choices for clean, super-efficient vehicles that
  meet market needs for price, size, capability,
  image, safety and performance.
• Because the automotive industry is stalled
  - legislation, regulation, labor issues,
  manufacturing costs, legacy costs, franchise
  laws, obsolete technology, consumer attitudes,
  and many other factors have combined to block
  breakthroughs.
• Because increases in engine efficiency have
  been "spent" on increased vehicle power,
  acceleration, and weight, rather than on
  increased fuel economy.
• Because we believe there is great
  opportunity for technological change.

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High level vision of the automotive X Prize

• Our goal is to stimulate automotive technology,
  manufacturing and marketing breakthroughs that
• Radically reduce oil consumption and harmful
  emissions
• Result in a new generation of super-efficient
  and desirable mainstream vehicles that people
  want to buy

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Usability Goals

• Components of a good usability goal
• Customer/user characteristics
• Task
• Metric
• Acceptance criteria

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Usability Goals

• 1. Identify customer characteristics from user
  personas
• Experience
• Exposure to system amount of training
• Education
• Attitude motivation

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Customer A white collar Netscape user for 4
years, uses the web daily, coming to our web site
for the first time
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Operational Definitions

• Define the user groups
• Novice
• Expert
• Casual
• Intermediate

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Usability Goals

• Ex Novice users (first time users) should take
  less than 2 minutes to search for price and
  availability information for a given product.
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• Ex Novice users (first time users) should find
  the specific product information faster and with
  less errors than with competitor application X.

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Usability Goals

• 2. Select a task from the task scenario
• Atomic or composite
• Relevant to customers task
• New concepts or mechanisms
• Critical features or mechanisms

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Task Determine the features of your low cost PC.
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• 3. Select a metric must be a measurable result
• Errors
• Interventions
• Time
• Reference used
• Percentage completed
• Indirect paths taken
• Satisfaction
• Preference

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• Where do we get these numbers?
• Metrics - compared against several different
  benchmarks
• Current level
• Minimum acceptable level
• Target level
• Optimal level

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Usability Goals

• Metric Can find the information in 2 minutes
  and give it at least an 8 on a satisfaction scale
  from 1 to 10.

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• 4. Select acceptance criteria
• Bounds for the metric (step 3)
• Number or percentage of times a single customer
  meets the criteria
• Number or percentage of customers who meet
  criteria

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• Acceptance Criteria to release At least 75 of
  all users are able to find information within
  metric.
• Nice-to-have Acceptance Criteria At least 90
  of all users are able to find information within
  metric.

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Priority Definitions

• How important is it to the final system
• Ex.
• Critical
• Required
• Depends on cost
• Desirable

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Exercise Team Meetings

• Break into teams
• Discuss deliverables for next class