Java Reference
In-Depth Information
an equivalent function key, or even a hotkey. That way, if your application is run on a platform
that does not have a mouse, the end user will still be able to navigate the application via the
keyboard.
An excellent final interface principle is to place items in stationary, predictable locations.
Following this principle helps the user develop what is known as muscle memory. The phe-
nomenon occurs when the user becomes so accustomed to the location of an item on the
screen that his or her mind subconsciously knows where it is located. Thus, working with the
interface becomes less thought-intensive and more like second nature to the user. For example,
think about the web browser you have used for the past three years. Even if you have switched
browsers numerous times, the Back and Forward buttons are almost always located in the
same place. Therefore, locating these buttons with the eye and targeting them with the mouse
has become quicker for you, basically because you always know where they are. It is like riding
a bicycle: You may stop riding for a few years, but you never forget how to keep your balance.
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Note
Users adapt to new UI standards, and therefore what is intuitive is always in flux. Over the years,
popular new UI concepts have been introduced. For example, when the tabbed panel metaphor was intro-
duced, it became an instant hit with developers since it offers a highly efficient method to display multiple
panels of data in a single window. Due to its efficient nature, the tabbed panel was, and still is, used quite
liberally by developers. Because the metaphor has been used so often, users have become accustomed to
using it. Some other examples of new UI paradigms that have entered the average user's interface vocabu-
lary include the icon button bar and the web browser-style “back and forward” navigational interface.
As you design and develop an interface for your application, it's always a good idea to test
it. Testing an interface isn't as cut and dried as testing application code, however. The best way
to test the GUI is to have someone who has never seen or used the application sit down and
use it.
First, create an interface prototype. The prototype can be a simple, nonfunctional version
of the proposed interface. At this stage, even an interface mock-up sketched out on paper is
sufficient. The point is, don't put too much work into a prototype before you're certain of its
usability value.
Next, present the test subject with a written list of tasks and ask the user to complete
those tasks. Observe the user while they attempt to complete the list using your interface pro-
totype. While you observe the tester, do not instruct them on how to get past areas they may
misinterpret or get hung up on. During this process, expect the user to get hung up on your
interface prototype and fail at some tasks. This is very common, so be careful not to become
aggravated with the testing process. When hang-ups occur, simply ask the test user what they
are trying to accomplish and the location where the user expects their next action. Take note
of these comments—they are actually suggestions on how to adjust the interface for the next
user. Continue this process as many times as you see fit or until the supreme moment when
all your testers can use the interface with few or no problems. For more extensive information
on usability testing and usability design issues in general, please refer to the FAQs section of
this chapter for some valuable URLs.
