Developing ResearchBased Guidelines for Improving Access to Small Screen Displays

1
Developing Research-Based Guidelines for
Improving Access to Small Screen Displays

• August 24, 2006 Presentation by Lee Huffman
• National Technology Associate
• American Foundation for the Blind

2
The Problem

• Small screen displays are difficult to read!
• Small Screen displays are EVERYWHERE!

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Some Devices That Use Small Screen Displays

• Telephones
• Office Equipment
• Self Service Kiosks
• Electronic Equipment
• At Home Medical Devices

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Why Are Small Screen Displays Difficult to Read?

• Lack of an industry standard
• Lack of research based guidelines for
  manufacturers to follow

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Existing Guidelines

• The development of guidelines is seriously
  hampered by the sparcity of sound scientific data
  about the needs of people with disabilities,
  John Gill
• The role of these (TRACE) Guidelines, then, is
  more to raise the awareness and understanding of
  designers and to help them ask the right
  questions than to provide specific answers or
  numbers, TRACE
• The (TIA) guidelines are based on current human
  factors and disability literature as well as
  current design practices, TIA Access

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Developing Research-Based Guidelines for
Improving Access to Small Screen Displays

• Research Objectives
• Phase 1 Develop display measurement capability
• Phase 2 Conduct a visual performance study using
  people who are visually impaired
• Phase 3 Publish research findings in order to
  advocate for accessibility

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Display Metrics

• Video Electronics Standards Association (VESA)
• 5 Key Visual Display variables
• Contrast (The most important variable)
• Font
• Illumination
• Glare
• Hue

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Optical Instrumentation for Obtaining Display
Measurements

• Digital Camera
• Iriss (2)
• Integrating Sphere
• Spectrometer
• Radiometric Calibration standard

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Predicting a Displays Required Contrast

• By obtaining a displays level of contrast and a
  persons contrast sensitivity level, one should
  be able to predict whether a display will be
  readable.
• A visual performance study can be used to verify
  predictability for a variety of visually impaired
  individuals.

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Phase 2 Visual Performance Study

• This study is to determine to what extent
  character recognition in small screen displays
  correlates to displayed contrast levels.
• A strong correlation could serve as a key
  guideline for designing accessible small screen
  displays.

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Phase 2 Visual Performance Study

• Fifty people with known Contrast Sensitivity
  levels, each having different levels of best
  correctable vision, will be asked to identify
  characters on a display.
• The percent of correct responses will be recorded
  for each person for each image.

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Phase 3 Publishing Research Findings

• In order to gain the attention of industry, the
  research findings will be published in scientific
  journals.

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ConclusionOne Step Closer to Accessibility

• Armed with a standard and measurement data that
  identifies the limitations of existing displays,
  consumers and advocates will have the leverage to
  push manufacturers toward accessibility.