Documents / Report
This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 1 November 2010, is one of a series of advanced technology reports produced in FY 2009 under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It proposes a provisional cockpit design for craft driven by speculative breakthrough propulsion, such as control of gravity and inertia and faster-than-light travel. It draws mainly on the book Frontiers of Propulsion Science and on human-machine interface research.
UNCLASSIFIED1·/r&I\ &PPIEIAL USE &ICLI Dwell and Reaction Time It takes about 0.4 to 0.6 seconds of dwell time at a particular display to extract the necessary quantitative information and at least 0.125 to 0.2 seconds for a qualitative recheck to reaffirm the reading has not significantly changed. In addition, the pilot needs another 0.125 to 0.2 seconds to act on that information. 28 Taken together, this creates a total response time of 0.7 to 1.0 seconds between first looking at a display and commanding the appropriate response. As an aside, displays whose update rates exceed this dwell time cannot be accurately read. This means that displays should be slowed down to the rate at which humans can absorb their information, roughly a half-second. Tunnel Vision While under stress, humans tend to narrow their visual attention, often fixating on a single central display or task: the greater the stress, the greater the narrowing. Humans are oblivious to this effect as it is happening. (As an aside, hypoxia-breathing insufficient levels of oxygen-induces the same effect and can be used to simulate this condition during training.) Peripheral vision is ignored, although some evidence suggests that spatial peripheral cues are subconsciously retained. This tunnel vision tendency cannot be prevented, but can be accommodated by providing the most critical information on the central display in a natural symbolic format. 29 Forgetful Visual Scanning Humans tend to lose track of when they last looked at a particular area of information, sometimes forgetting to recheck parameters when needed. 30 This is where automated checklists can help, 31 as well as vehicle management systems that process the vehicle's situation and then recommend the best corrective measures. Limiting Options Humans tend to be able to retain only about 3 to 10 different items in short-term memory. Some studies focus on seven items as the optimum. Thus, it is recommended in quick-selection menus, or when designing hierarchical categorizations, to have no more than four to seven items per level. For groupings of information that are not needed during critical moments, these constraints can be relaxed, but with the added consequence of requiring significantly more browsing time. Adaptive Display Errors In computer displays having multiple layered windows, or where the display changes in different situations, it is common that a user will lose track of how their current display image relates to the whole system. 32 This problem is called "getting lost" or referred to as a "keyhole" error. To prevent this error, it is best to simultaneously display some schematic indicator of where the user is in the system. This requires a pictorial representation of the relations of the system's operational windows. This situation is consistent with the evidence that humans tend to rely on a physical model for where to 22 UNCLASSIFIED,','Flilll. lilFFUilAle lal!i! 8Hl!V
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 57 pages are in the text index: search them above, or from the library's search.