Chapter 25 Flashcards
PoHCI, week 2 (9 cards)
What is the defining objective of a display?
To transform digital information into analog information so that people can accurately perceive in one or more sensory modalities
What is encoding and rendering?
Encoding: The basic operation of turning digital information into something that a display may show
Rendering: The operation of transforming the encoded information into something that can be
perceived by people
What are the three types of values for encoding?
Nominal variables - names, zip codes etc
Ordered variables - level of education, satisfaction rating etc
Quantative - temperature, pulse, level of rain fall etc
What is visual encoding?
A type of encoding separated into visual marks and channels
Visual marks: Geometric primitives such as points, areas, and lines.
Visual channels: The position of a mark, its color, and its texture
What are the three color dimensions?
Hue: Red, green and blue
Value: Intensity of the color from dark to full brightness
Saturation: Depth of the color, depends on amount of the color
What is the spatial- and temporal resolution in terms of displays?
Spatial: pixels per inch or similar
Temporal: Refresh rates (hertz)
What is haptics?
Haptic technologies enable users to perceive touch, or, in general, forces on their body
What is force feedback?
A force feedback device is a system that generates a perceived force by actuation
What are the three criteria for effective force feedback?
Free space must feel free
Solid virtual objects must feel stiff
Virtual constraints must not be easily saturated
