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Chapter 8: Displays

System

Display (the represented system) Mental model

Senses

AttentionPerception

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Display design principles

Perceptual principles1) Absolute judgement (maximum of 5-7 levels)2) Top-down processing (Highlight the unexpected)3) Redundancy gain (Multiple cues or modes)4) Discriminability (ratio of similar to dissimilar features)

Attention principles5) Minimizing information access cost (minimize “distance” between variables)6) Proximity compatibility principle (link variables through common location, color, or other code)7) Principle of multiple resources (distribute information between mental resources)

Mental model principles8) Principle of pictorial realism (configure to match system/mental model, thermometer)9) Principle of the moving part (match movement to system/mental model, aircraft and altimeter)10) Ecological interface design (display provides an externalized and normative mental model)

Memory principles11) Predictive aiding (show future states rather than force people to estimate)12) Knowledge in the world (displayed information rather than rely on memory)13) Consistency (same cues should have same meaning, red is for danger)

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Attention principles

Minimizing information access cost (minimize “distance” between variables, same page for related information)

Proximity compatibility principle (link variables through common location, color, or other code)

Principle of multiple resources (distribute information between mental resources, such as auditory and visual modes)

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Mental model principles

Principle of pictorial realism (configure to match system/mental model, thermometer)

Principle of the moving part (match movement to system/mental model, aircraft and altimeter)

Ecological interface design (display provides an externalized and normative mental model)

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VCR metaphor for printer?

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Dimmer Switch

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Memory principles

Predictive aiding (show future states rather than force people to estimate)

Knowledge in the world (displayed information rather than rely on memory, position estimates on chart)

Consistency (same cues should have same meaning, red is for danger)

8 From Barrows and Powell (2000)

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Display design principles

Perceptual principles1) Absolute judgement (maximum of 5-7 levels)2) Top-down processing (Highlight the unexpected)3) Redundancy gain (Multiple cues or modes)4) Discriminability (ratio of similar to dissimilar features)

Attention principles5) Minimizing information access cost (minimize “distance” between variables)6) Proximity compatibility principle (link variables through common location, color, or other code)7) Principle of multiple resources (distribute information between mental resources)

Mental model principles8) Principle of pictorial realism (configure to match system/mental model, thermometer)9) Principle of the moving part (match movement to system/mental model, aircraft and altimeter)10) Ecological interface design (display provides an externalized and normative mental model)

Memory principles11) Predictive aiding (show future states rather than force people to estimate)12) Knowledge in the world (displayed information rather than rely on memory)13) Consistency (same cues should have same meaning, red is for danger)

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Types of displays

Alerting Labels Monitoring Multiple displays Navigation displays and maps Tables and graphs

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Alerting

Perceptual: Redundancy gain (use auditory because it is omnidirectional)

Perceptual: Absolute judgement (limit number of warning tones to 5-7)

Memory: Consistency (uniform meaning for color codes)

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Labels

Perceptual: Discriminability Attention: Proximity compatibility principle Asymmetry in interpretation of negative

• Right turn only vs. No left turn

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Monitoring

Perceptual: Absolute judgement and display markings

Mental model: Ecological interface design Mental model: Principle of pictorial realism and

analog and digital displays. DEPENDS ON TASK

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Traditional Interface

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Rankine Cycle Interface

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Specific benefits of the Rankine cycle display

Distinctive shape makes changes easy to identify (highlights the unexpected)

Changes in shape are linked to a model of the underlying physics and so support problem solving (externalized mental model)

Temperature and pressure data are placed in a meaningful context (Knowledge in the world rather than steam tables in the head)

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Multiple displays

Attention: Minimizing information access cost using the primary visual area, phase-related tailoring

Memory: Consistency of display layout

Attention/Mental model: Information grouping

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Multiple displays

Attention: Costs and benefits of head-up displays

Perceptual: Discriminability and emergent features of configural displays

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Navigation displays and maps

Perceptual: map clutter (color, intensification, and declutter/filtering functions)

Map orientation: Head up vs North up

3-D vs 2-D: Role of topography, experience of users;

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Tables and graphs

Perceptual: Discriminabilty, differentiating lines in a line graph

Perceptual: Discriminabilty, minimizing clutter

Attention: Proximity compatibility and linking lines to legend

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Objectives

Power of representation Display variables and the match to the task Display design principles

• Perceptual• Mental model• Attention • Memory

Types of displays and how to apply the principles