1.1 MINIMIZE THE MENTAL CONSTRAINT ON THE USER GENERALLY, ONE OF THE...

7.1.1 Minimize the mental constraint on the user

Generally, one of the most important aspects to take under consideration while designing

a graphical user interface, is to lower the users cognitive load, not having to remember a

high level of details. This is especially important since the crew controller works with a

large amount of data in a stressful environment, which affects the user’s level of

concentration, increases the distractibility and reduces the short-term memory capacity.

This helps provide the user with a mental model of the system, which is coherent with

the design model. A correct mapping of the user model and the design model is the goal.

Even though too much information can be cognitively straining, the same effect

is achieved when providing the user with too little information; if important information

is suppressed then the user will spend time looking for it. Humans have a natural talent

for selecting which information to process, which should be taken advantage of.

Keeping the number of components of which the Operations Monitor consist to a

minimum means the crew controller will have less to keep in mind at any given time.

These components should also be placed in and aligned to a static frame. Also, the

Operations Monitor should be kept in one window. If the user opens another process, it

should be presented somewhere in the Operations Monitor. If the user must switch

often between several windows or views, his or her cognitive strain will increase,

inducing the feeling of “getting lost”.

If the user wishes to handle several alerts at the same time, use the split-screen

method, splitting the screen space into several parts, homogeneous in appearance, and

placing each alert in a separate part. This way, the alerts are comparable by the user and

the user avoids “getting lost” in different windows. Provide the user with the alternative

to clear the entire screen if required, instead of manually having to shut down the

different “information containers” that may be open.