Icons are small pictorial symbols used on computer menus, windows, and screens
representing certain capabilities of the system. An icon may be any symbol, image or
pictograph used to represent a concept, idea or physical object. Their application provide
the following benefits:
- They can support of the extensive human ability of pattern recognition.
- They can offer language independence to use of products in different countries.
- They reduce required space for information presentation.
- They offer a certain level of aesthetic appeal.
However, the design of icons for a device has to be carried out with care if they are
to be effective. Attributes of good icons are described under the following headings:
Easy association with the message
An icon can represent a function or feature in a number of ways. There are a number ways
in which an icon can represent its underlying concept. These are: 'resemblance',
'exemplar', 'symbolic', or 'arbitrary'.
- Resemblance
- icons present a direct or analogous image of the function or concept itself. Thus, the
road sign for "falling rocks" presents a clear resemblance of the roadside
hazard. The trash can on the Macintosh desktop is another example of an icon resembling
its function.
- Exemplar
- icons provide examples to represent their meaning such as a knife and fork used in the
public information sign to represent "restaurant services". The image shows the
most basic attribute of what is done in a restaurant i.e. eating.
- Symbolic
- icons are used to convey the underlying referent that is at a higher level of
abstraction than the image itself e.g. the picture of a wine glass with a fracture to
convey the concept of fragility.
- Arbitrary
- icons bear no relationship to their intended meaning so the association must be learned
e.g. the bio-hazard sign consisting of three partially overlaid circles. Note that
arbitrary icons should not be regarded as poor designs, even though they must be learned.
Such symbols may be chosen to be as unique and/or compact such as a red no entry sign with
a white horizontal bar, designed to avoid dangerous misinterpretation.
Distinguishable from other symbols
Where a range of icons are needed for related functions, similarity between icons can
be useful. For example, if an up arrow is used to indicate the movement of a selection bar
upwards through a menu list, then a down arrow will be taken to mean movement downwards
through the list. However, if too many similar symbols are used for different functions,
this can cause confusion. For example, three clock symbols are shown on a teletext
handset: one to display the time, one to set a time when a page is displayed and a third
to cancel that time.
Not overly complex
A common problem with icon design is excessive complexity. An icon may be designed on a
large scale which is then hard to recognise when reproduced on a smaller scale on a
key-top. In a teaching exercise to design icons for telephone functions that HUSAT
occasionally carries out, delegates or students often draw complex icons that would need
to be greatly simplified to be practical. As well as being distinctive, icons which are
not too complex are also more easily reproduced on different displays at varying scales
and resolutions. Thus, after initial design, an icon should be constructed using the size
of pixel grid e.g. 18x20, in which they will be displayed. Also by proving redundancy
within an icon, this will make it more distinguishable. As shown below the use of the hair
bow emphasises that one person is a child and the other an adult:
Can be combined to represent interrelated concepts
By making a good choice of icon elements, they provide a rich symbolic language. If one
can learn the meaning of the basic elements, the combined elements become more
self-explanatory. For example, using the VCR 'play' symbol (a right facing arrow) to
represent standard play speed, two arrows gives an indication of a faster speed.
Suitable for different cultures and uncontroversial
Some symbols may be inappropriate for certain cultures. For example, the red cross symbol
for medical facilities is not used by Moslem populations. Similarly, a Œthumbs upš
symbol, representing OK, is regarded as a crude gesture in certain countries. Furthermore,
the use of images which use exclusively gender specific representations should not be
used.
Accords with international or accepted standards
Where existing standards and conventions exist, these should be used in preference to
creating new icons unless there is reason to be believe that an icon will not be
understood. For example, the TV icons for brightness, colour and contrast control are
widely used and so alternatives are unlikely to replace them in the foreseeable future.
Icon standards for IT are now being established by bodies such as the ISO committee
ISO/IEC JTC 1/SC/18.
Fallacies
Finally some common fallacies about icons are: that the designer can use icons to totally
replace words, that icons necessarily make products easier to use, and that an icons must
be perfectly obvious in order for them to be good ones.
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