Chapter 6: Direct Manipulation and Virtual Environments
6.3 Explanations of Direct Manipulation
Problems with direct manipulation
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Spatial or visual representations can be too spread out
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High-level flowcharts and database-schema can become confusing
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Designs may force valuable information off of the screen
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Users must learn the graphical representations
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The visual representation may be misleading
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Typing commands with the keyboard my be faster
The OAI Model explanation of direct manipulation
Portrait of direct manipulation:
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Continuous representation of the objects and actions of interest
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Physical actions or presses of labeled buttons instead of complex syntax
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Rapid incremental reversible operations whose effect on the object of interest
is immediately visible
Beneficial attributes:
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Novices learn quickly
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Experts work rapidly
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Intermittent users can retain concepts
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Error messages are rarely needed
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Users see if their actions are furthering their goals
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Users experience less anxiety
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Users gain confidence and mastery
