User Interface Design and Ergonomics - National Open University of ...

M cones, or, misleadingly, green cones) is most sensitive to light perceived as green, with
wavelengths around 534 nm.
3.4.1 Facts about colour
Colour can be a powerful tool to improve user interfaces, but inappropriate use
can severely reduce human performance
Colour can be very helpful in gaining the attention of users
In designing user interfaces, pay attention to how to combine colours and human
perception
Consider people with colour deficiency in your colour combination. The colour
limitations such as color blindness, near/far sighted and focusing speed should be
considered.
As we age, sensitivity to blue is even more reduced and perceive a lower level of
brightness. The implication is that you do not rely on blue for text or small
objects.
Red objects appear closer than blue objects
3.5 ATTENTION
Attention is the cognitive process of selectively concentrating on one aspect of the
environment while ignoring other things. Examples include listening carefully to what
someone is saying while ignoring other conversations in a room (the cocktail party effect)
or listening to a cell phone conversation while driving a car. Attention is one of the most
intensely studied topics within psychology and cognitive neuroscience.
It is the taking possession by the mind, in clear and vivid form, of one out of what seem
several simultaneously possible objects or trains of thought. Focalization, concentration,
and consciousness are of its attributes. It implies withdrawal from some things in order to
deal effectively with others, and is a condition which has a real opposite in the confused,
dazed, scatterbrained state.
Our ability to divide our attention among multiple tasks appears to depend on two things.
First is the structure of the tasks that are trying to share our attention. Tasks with
different characteristics are easier to share; tasks with similar characteristics tend to
interfere. Important dimensions for task interference seem to be the modality of the
task’s input (visual or auditory), its encoding (e.g., spatial/graphical/sound encoding, vs.
words), and the mental components required to perform it. For example, reading two
things at the same time is much harder than reading and listening, because reading and
listening use two different modalities.
The second key influence on multitasking performance is the difficulty of the task.
Carrying on a conversation while driving a car is fairly effortless as long as the road is
familiar and free of obstacles; when the driver must deal with traffic or navigation,
conversation tends to slow down or even stop.
66