Principles and Behaviours Models of HCI
Principles of design
A computer’s interface is seen differently by different people by the way they perceive the interface
through colour, pattern/layouts, and visible objects. It is important for designers and developers to use
certain rules, systems, and models to understand how to create a HCI that users will enjoy and comfortably
use while designing to avoid constraints due a user’s eyesight or navigational abilities.
Colour:
The trichromatic system is a theory that there are three sets of colours -that
correspond to three different cone receptors within our eye’s retina that define the
way we see colour. This was founded on an experiment of three different lights
emitting wavelengths of different colours to produce a mixture field that matched
the visual colour of a single wavelength. The balance of colour vision is now known as
blue (short wavelengths), green (medium wavelengths), and red (long wavelengths).
This theory has been developed into there being three opponent colour channels
(red/green, yellow/blue, and black/white), these pairs of colours do not mix; in
addition, people with colour vision disabilities confuse yellow and blue or red and
green so these colour match-ups should not be used in user interfaces.
Luminance is a metric measure that measure the intensity of light per unit area, this shows how bright a specified
area is due to light emitted from or passing through to the specified direction/angle. The colour contrast of certain
objects in an interface bring attention to themselves to show priority and importance, the luminosity could also
change to indicate where or what the user should do next. Screen brightness overall is important, for private devices
like smartphones users can control their screen brightness and have it on auto to adapt to the environment’s
lighting, auto-adapt must also be on public systems so users can view the screen at any time of day and in any
weather.
The ‘pop out’ effect is the simple principle of emphasising text, images, and objects by making them different or
brighter colours, using the bevel effect, and underlining text to show important content on an interface. If all of an
interface’s attributes where in the foreground/background, this would make it very hard to distinguish differences
such as what is a button or link. The ‘pop out’ effect ensures that our eyes can immediately tell the difference so that
an interface is comprehensible.
Pattern:
Proximity is the distance between objects – in terms of HCI, objects/images/text should be equal proximity
to each other which allows for a neat display that is easier to view and find what the user wants. An
example of this is apps on game consoles, desktops, and smartphones have the equal distance between
them in a grid format.
Continuity is to have a feature or pattern continuous throughout a certain time or interface. A layout of an
interface should be continuous as the user remembers where everything was on a previous page or when
previously used so a change in pattern would take the user’s brain longer to process. For example, the
layout of a webpage’s header and footer should not be changed by having continuity with the navigation,
the user will not have to look but uses the HCI without second thought.
Principles of design
A computer’s interface is seen differently by different people by the way they perceive the interface
through colour, pattern/layouts, and visible objects. It is important for designers and developers to use
certain rules, systems, and models to understand how to create a HCI that users will enjoy and comfortably
use while designing to avoid constraints due a user’s eyesight or navigational abilities.
Colour:
The trichromatic system is a theory that there are three sets of colours -that
correspond to three different cone receptors within our eye’s retina that define the
way we see colour. This was founded on an experiment of three different lights
emitting wavelengths of different colours to produce a mixture field that matched
the visual colour of a single wavelength. The balance of colour vision is now known as
blue (short wavelengths), green (medium wavelengths), and red (long wavelengths).
This theory has been developed into there being three opponent colour channels
(red/green, yellow/blue, and black/white), these pairs of colours do not mix; in
addition, people with colour vision disabilities confuse yellow and blue or red and
green so these colour match-ups should not be used in user interfaces.
Luminance is a metric measure that measure the intensity of light per unit area, this shows how bright a specified
area is due to light emitted from or passing through to the specified direction/angle. The colour contrast of certain
objects in an interface bring attention to themselves to show priority and importance, the luminosity could also
change to indicate where or what the user should do next. Screen brightness overall is important, for private devices
like smartphones users can control their screen brightness and have it on auto to adapt to the environment’s
lighting, auto-adapt must also be on public systems so users can view the screen at any time of day and in any
weather.
The ‘pop out’ effect is the simple principle of emphasising text, images, and objects by making them different or
brighter colours, using the bevel effect, and underlining text to show important content on an interface. If all of an
interface’s attributes where in the foreground/background, this would make it very hard to distinguish differences
such as what is a button or link. The ‘pop out’ effect ensures that our eyes can immediately tell the difference so that
an interface is comprehensible.
Pattern:
Proximity is the distance between objects – in terms of HCI, objects/images/text should be equal proximity
to each other which allows for a neat display that is easier to view and find what the user wants. An
example of this is apps on game consoles, desktops, and smartphones have the equal distance between
them in a grid format.
Continuity is to have a feature or pattern continuous throughout a certain time or interface. A layout of an
interface should be continuous as the user remembers where everything was on a previous page or when
previously used so a change in pattern would take the user’s brain longer to process. For example, the
layout of a webpage’s header and footer should not be changed by having continuity with the navigation,
the user will not have to look but uses the HCI without second thought.
