An Approach to Measuring Tactile Aptitude

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An Approach to Measuring Tactile Aptitude

• Ben P Challis Alistair D N Edwards
• Department of Computer Science
• University of York
• http//www.cs.york.ac.uk/alistair

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How well can you see?
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How well can you feel?

• Who knows?

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If you build a tactile diagram and people cannot
use it

• is the diagram to blame
• or the user?
• Need for a test

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Note

• It was the approach to testing that was under
  investigation
• Not the particular designs
• Nor the individual participants

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Skills to test

• Line-tracing
• Point symbol recognition
• Areal symbol recognition
• Line symbol recognition
• Height discrimination
• Exploration strategy
• Distinctive features analysis

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Pilot tests

• Blindfolded, sighted participants

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Line-tracing

• 3 tasks
• Same components
• Acute angles
• Right-angles
• Curved areas
• Observation

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Point symbol recognition

• 3 groups, progressive difficulty
• Match the target in the set
• Most people could not get past first group

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Point symbols
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Areal symbol recognition

• Matching target to a set
• Latched on to textures

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Line symbol recognition

• Line widths
• Parallel lines versus single lines
• Line types

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Line widths

• different/same/dont know

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Parallel lines

• Different line widths separations
• 1 or 2?

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Line types

• Set of dotted and dashed lines

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Height discrimination

• Comparisons
• Which is higher - or the same?

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Exploration strategy

• Explore a diagram
• Observation
• Could not observe whether a strategy worked
• Need a more focused test

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Distinctive features analysis

• Can people home in on the critical features?
• e.g. corners of a square
• Too many permutations

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Lessons

• Tailor the test
• Fatigue is significant
• physical and mental
• Reduce the variations
• Use one material
• Immediate recognition

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Core set

• Line width
• Parallel lines
• Point symbols
• Areal symbols
• Line tracing

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Further work

• Better investigation of exploration strategies
• Distinctive features analysis
• Open point symbols
• Quantitative tests