Firm foundation in the main hci principles, the book provides a working

Figure 3.10 Color specification by hue (particular/dominant wavelength), saturation (relative dif-
ference in the major wavelength and the rest), and value/brightness (total amount of the light energy).

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H U M A N FA C T O R S A S H C I T H E O R I E S
consolidated for conscious recognition (of a larger object) through the 
visual information processing pipeline, pre-attentive features might 
be used to attract our attention. Pre-attentive features are compos-
ite, primitive, and intermediate visual elements that are automatically 
recognized before entering our consciousness, typically within 10 ms 
after entering the sensory system [12]. These features may rely on the 
relative differences in color, size, shape, orientation, depth, texture, 
motion, etc. Figure 3.12 shows several examples and how they can be 
used collectively to form and design effective graphic icons.
At a more conscious level, humans may universally recognize certain 
high-level complex geometric shapes and properties as a whole and 
understand the underlying concepts. Figure 3.13 shows examples of such 
universally accepted (across different cultures) geometric diagrams with 
0
1
2
3
4
5
0
1
2
3
4
5
Figure 3.11 Coding of information in a map (e.g., temperature levels) using contrast in bright-
ness (left) and color (right). (From Hemer, M. A., Fan, Y., Mori, N., Semedo, A., and Wang, X. L., Nature 
Climate Change, 3, 471–476, 2013 [11].)
Red: Enemy
Blue: Friendly
Green: Unknown
Icons: Aircraft (triangle), Infantry (circle), Tanks (rectangle)
Figure 3.12 Examples of preattentive features for attention focus based on differences in size, 
shape, and orientation (left) and application to icon design (right). (From Ware, C., Information 
Visualization: Perception for Design, 3rd ed., Morgan Kaufmann, Waltham, MA, 2012 [12].)

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H U M A N – C O M P U T E R I N T E R A C T I O N 
the connotation of, e.g., connection/relation, dependency, causality, 
inclusion, hierarchy/structure, flow/process, etc.
3.2.2 Aural
Next to the visual, the aural modality (sound) is perhaps the most 
prevalent mode for information feedback. The actual form of sound 
feedback can be roughly divided into three types: (a) simple beep-
like sounds, (b) short symbolic sound bytes known as earcons (e.g., the 
paper-crunching sound when a file is inserted into the trashcan 
for deletion), and (c) relatively longer “as is” sound feedback that is 
replayed from recordings or synthesis. As we did for the visual modal-
ity, we will first go over some important parameters of the human 
aural capacity and the corresponding aural display parameters.
3.2.2.1 Aural Display Parameters
• Intensity (amplitude) refers to the amount of sound energy and 
is synonymous with the more familiar term, volume. Intensity 
Diagram
Meaning
Relation/Path
between Objects
Types/Strength of
Relations
Inclusion, Structure,
Hierarchy
Order, Causality,
Flow, Process,
Dependency