Perception:
Perception is our awareness and understanding of the elements and
objects of our environment through the physical sensation of our
various senses like sight, sound, smell and so on.
We tend to match objects or sensations
perceived to things we already know.
The goal in design is to utilize
perceptual capabilities so screen can be structured in the most meaningful and
obvious way.
Perceptual characteristics include the
following:
Proximity: Our eyes and mind see objects
as belonging together if they are near each other in space.
Similarity: Our eyes and mind see objects
as belonging together if they share a common visual property such as color,
size, shape, brightness or orientation.
Matching patterns: We respond similarly
to the same shape in different sizes.
Succinctness: We see an object as having
some perfect or simple shape because perfection or simplicity is easier to
remember.
Closure: If something does not quite
close itself such as circle, square, triangle, or word we see it as closed
anyway.
Unity: Objects that form closed shapes
are perceived as a group.
Continuity: Shortened lines may be
automatically extended.
Balance: We desire stabilization or
equilibrium in our viewing environment. Vertical, horizontal and right angles
are the most visually satisfying and easiest to look at.
Any
direction the interface is comfortable to the user
Expectancies: We perceive not what is
there but what we expect to be there. We see not how a word is spelled but how
we expect to see it spelled.
Exist,
not exist
Context: Two drawn lines of the same
length may look the same length or different lengths depending on the angle of
adjacent lines or what other people have said about the size of the lines.
Signals versus noise: Our sensing
mechanisms are bombarded by many stimuli some of which are important some of
which are not. Important stimuli are called signals and not important or
unwanted are called noise.
Stimulus
…..Noise signal both remove noise,
process signal
Memory:
Memory
is viewed as consisting of two components
Long-term
and short-term memory.
Short-term or working memory receives information from either senses or
long-term memory or from both at once as the senses being processed separately.
Information stored within short-term
memory varies from 10 to 30 seconds and the memory storage capacity has gradually
being lowered from Miller’s 7±2 items to
a size of 3-4 items.
Long-term memory contains the knowledge
we possess. Information received in short-term memory is transferred and
Encoded
to it in process known as
Learning.
Minimize the need for mighty memory in
the design.
Sensory Storage:
Sensory storage is the buffer where the
automatic processing of information collected from our senses takes place.
It is an unconscious process, large, attentive to the environment, quick
to detect changes and constantly being
Replaced by newly gathered stimuli. Conscious and unconscious
Repeated and excessive stimulation can
fatigue the sensory storage mechanism, making it less attentive and unable to
distinguish what is important. Put
less
Eliminating interface noise will ensure
that important things will be less likely to be
missed.
Visual Activity:
The capacity of the eye
to resolve details
is called visual activity.
The eye’s sensitivity increases for those
characters closest to the fixation point and decreases for those characters at
extreme edges of the circle.
Patterns for fill in areas of screens
must be carefully chosen to avoid visual distraction as the eyes tremble
slightly.
Foveal “retina” and Peripheral Vision:
Foveal vision is used to focus directly on
something and peripheral vision senses anything in the area surrounding the
location we are looking at.
Peripheral vision is thought to provide
clues to where the eye should go next in the visual search of a screen.
Patterns,
Shapes and
Alignment
Peripherally visible can guide the eye in
a systematic way through screen.
Information Processing:
There are two levels of information
processing
Higher level &
Lower level.
Highest level is identified by
consciousness and working memory which is slow,
limited and sequential which is used for reading and understanding.
Lower level is identified without
conscious effort and processes familiar information rapidly and the limit of its
capacity is unknown.
Visual distinctiveness of a
screen is strong contributor. If a screen is jammed with information and
cluttered it loses its uniqueness and causes more time consuming reading
process.
Mental Models:
A mental model is simply an internal
representation of a person’s current understanding of
something.
A person already familiar with one
computer system will bring to another system a mental model containing specific
visual and usage expectations.
If the new system complies with already
established models it will be much easier to learn and use.
Movement Control:
Provide large objects for important
functions.
Take advantage of the pinning
actions of the sides, top, bottom and corners of the screen.
