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Users, Usability
and Functionality
Maximum usability is an objective of any type of interactive multimedia
application. Usability is assessed by how easy or difficult it is to interact
with an application. Presentations are useable if the interactive elements
are functional, meaning they not only work, but work in a way that the
user expects.
To achieve functionality, users should not
be distracted from the function of a particular scene. For example, an
animating object can be distracting and make it difficult to read text
placed next to it. Bad choice of colours or inappropriate use of sound
can also be distracting.
The usability of applications depends predominantly on the user, the target
audience. Understanding the capabilities and limitations of your audience
allows your presentation to be designed as suitable as possible to their
needs. A user that is experienced with multimedia applications would have
different needs to a novice. A simpler and clear navigational structure
is more appropriate to novice users while advanced users could cpoe with
more complex, animated interaface.
You may develop multimedia work for people with special needs. These may
include people with hearing impairment, sight impairment or mobility impairment.
A colour code to specify actions, for an audience that may be colour blind,
would not be useable. People with hearing difficulties may require control
of volume to a greater degree.
The cultural background of your audience is also an important consideration.
Slang or colloquial terms used in a presentation may not be understood.
If humor is used, it may not translate well to different cultures. The
use of religious symbols or national emblems could offend your audience.
While metaphors and analogies are usually helpful, it can cause problems
to an international audience. Metaphors that are not universal can be
misunderstood.
The key areas of usability include developing a clear navigational structure,
careful interface design and consistency. These areas are not mutually
exclusive.
Navigation Structure
When designing a presentation to achieve maximum usability, the path through
which the user navigates should be clear and easy to follow. If you use
any special symbols or icons to help in navigation, these should be explained
at the beginning of the presentation. Whatever the nature of the presentation,
keeping the navigation simple will enable the user to understand it quickly
and interact with it easily.
Contextual referencing is important to give
the user orientation within a presentation. For example, if there are
10 slides in a section and currently the scene shows slide 3, a title
saying “Slide 3 of 10” gives context to a user. If you are
displaying a long animation or video, a progress bar can show how far
you are into the segment, how long it is taking to play and how long it
will take to finish. Contextual referencing is especially important for
long presentations, where your audience may lose concentration and later
try reorient him/herself. A user should at all times know where he/she
is in the navigational structure and how to get to another point within
it.
It is important to maintain a logical progression through a presentation.
If you use a hierarchical tree structure, it is better to present the
simpler information at the top of the tree and then more complex material
towards the end. A presentation should take the audience through the information
in an order that makes sense and builds on what has been learned/seen
before.
Websites are a good source of learning about navigational structures.
Since they are designed for a wide audience group, the navigation must
be as clear and understandable as possible.
Examples:
Macromedia
The Macromedia website has a clear navigational structure. The main categories
always appear at the top of the page and occasionally, you can expand
categories further, as shown in this example on the right hand side of
the page.
Apple
The Apple website allows the user to know where he/she is at all times.
The main sections are located in tabs at the top of the page. Clicking
one of them activates it. The color changes and submenus appear. Navigation
is clear and simple.
Read more about Guidelines for designing a useable
graphical interface here.
If you have any feedback on this article, feel free to let us know at:
feedback@multimediacreative.com.au
©
2003 Multimedia Creative
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