Design of information Display Systems for Air Traffic Control - FAA

Consistency in the design of a system can reduce training time, facilitate execution of functions,
and improve the user’s ability to access information (HF-STD-001, 2.3.1). With experience, the
user learns the placement of links, the location of functions, and the organization of the system.
To the extent possible, designers should maintain consistency throughout the system. The users
should perform similar functions in similar ways and find them in consistent locations (HF-STD-
001, 2.6.9). For example, the Print command should always be located in the same menu or
location on the display, and it should always produce the same type of system response. Figure 7
illustrates consistency in the design and implementation of a navigation bar. The bar is available
on every page, in the same location, and with the same set of buttons.
Figure 7. An illustration of consistency in the design and implementation of a navigation bar.
Design inconsistencies have user performance consequences. When users encounter an
unfamiliar design scheme, they must visually scan each page to determine the location of
buttons, navigation bars, and other elements. Consequently, the amount of time needed to find
information increases and search efficiency decreases. The users lose the benefits that come
from using a system with a consistent design scheme.
Standard 1: Information on an IDS shall be accessible.
The following guidelines address the issues of physical accessibility, organization of
information, navigation, and consistency. Although the guidelines refer to buttons as links to
information, there are other ways of implementing links that would be equally effective.
(1.1) The system display should be located such that the user can see it and interact
with it.
(1.2) Information should be organized by category and by an operationally
relevant/meaningful scheme (HF-STD-001, 8.1.3.9).
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