Sound & Displays Control Panel
Lisa served as design lead for this
project, first as an Apple Employee and then as a consultant. She
participated in the project from initial conception through
shipping. The design process included five rounds of usability
testing, two of which Lisa conducted. The following text and
screenshots are taken
from the 30-page "Human Interface Specification" she wrote for this
Lisa is co-inventor on two U.S. utility patents awarded to
Apple as a result of this project.
Function of EZAV
The Sound & Displays Control Panel (project name EZAV) is an
application that resides in the Control Panels folder. It allows a
user to configure his or her Macintosh AV system, which is defined
as the sound and video input and output features, including devices
connected to (and controlled by) the CPU and the settings that
affect them. Configuration includes activating or deactivating input
and output devices as well as adjusting the various sound and video
settings. EZAV allows configuration of both built-in and added AV
Potential AV devices include:
Sound input - any
sound-producing device, including:
- CD players
- video cassette recorders
- audio cassette players
- telephone connections
Sound output - any sound-receiving
- video cassette
- audio cassette recorders
Video input - any
video-producing device, including:
- video cameras
- video cassette
- television tuners
Video output - any video-receiving
- television sets
- video cassette
Design goals, objectives, and rationale
The ultimate goal
of EZAV is to make the Macintosh AV features more accessible and
usable. An exhaustive survey of early buyers of the Cyclone products
(Centris 660AV and Quadra 840AV) discovered that many customers had
never used key AV features—not because didn’t need the features, but
because they found it too difficult to configure the system
properly. The specific goal of EZAV is therefore to make AV
configuration significantly easier—easy enough that customers will
make full use of their Macintosh’s AV features.
As part of our
effort to provide maximum ease-of-use in AV configuration, the
following design objectives were targeted:
- Allow users to
configure their entire AV system in a single control panel. One
reason why users find AV configuration to be such a chore is that
settings are currently housed in two separate control panels (Sound
and Monitors). Additional AudioVision display settings are found in
the Video control panel. Centralizing all the Sound and video
settings in a single control panel makes it easier for users to
locate needed settings.
- Provide users with a clear conceptual
model of their AV system. Users with little prior exposure to
computer AV systems have difficulty generating an accurate
conceptual model of the system and its pieces. Helping users
generate such a model helps ensure their success in configuring and
using the AV system.
- Make the user's interaction with the AV
system as a whole and with individual devices as straightforward and
consistent as possible. Currently, the Sound and Monitors control
panels have little UI design in common, so there is no interaction
consistency between the sound and video sub-systems. Furthermore,
the Sound control panel is itself inconsistent between modes.
Keeping interactions consistent across all AV devices and features
makes configuration tasks easier to understand and learn.
as few interaction “layers” (e.g., nested dialogs) as possible.
Navigation through multiple windows and dialogs can be distracting
and disorienting and makes learning more difficult. Keeping the
structure of the control panel simple and shallow minimizes the
cognitive demand placed on users simply for navigation.
modal interaction designs. Modal interaction designs (e.g.,
one-at-a-time panels activated by pop-ups) force a large part of the
user interface to be hidden. Users can only see a piece of the
interface and must depend on short-term (or eventually long-term)
memory to build a conceptual model of the system as currently
configured. Allowing users to see related settings simultaneously
allows them to develop a fuller picture of their system and the
relationships and dependencies among the various features and
- Provide effective visuals when needed for clarity. A
computer-based AV system is highly spatial and complex.
Supplementary visuals boost user understanding of complex spatial
relationships more effectively than text alone.
configuration changes to take effect immediately. If a user makes
several changes that later take effect simultaneously (e.g., on
close or restart), he or she may have difficulty sorting out which
setting change caused which effect. Minimizing the time between a
user's action and the computer's response makes it easier for him or
her to understand the implications of each setting.
- Allow users to
escape from mistaken configuration changes. None of the current
control panels allows users to undo changes. Instead, users must
remember what the previous settings were, and change them back.
Providing an escape route relieves users of this short-term memory
- Allow users to invoke default settings. Users sometimes
choose configuration settings that make their system work in ways
they did not anticipate. Providing default settings helps frustrated
users “start from scratch” on a problematic configuration task.
- Provide fast, easy access to frequently used settings. Accessing
settings via a control panel—however well-designed—is relatively
time-consuming, especially for frequently-used settings. Providing a
fast-access mechanism for key AV-related settings (color depth,
resolution, speaker volume, and file sharing) enhances the usability
of the AV features, especially for advanced users.
high-quality assistance for the AV features through Macintosh Guide.
A control panel is not an appropriate vehicle for detailed
explanations. High-quality assistance can help our users who lack
experience with Macintosh computers or AV equipment (or both).
Macintosh Guide can provide intelligent, context-sensitive help— but
only with careful planning of both the content of the assistance and
the coding requirements that allow Reno to be intelligent.
applications to change settings for the user. Because applications
cannot access key AV settings (e.g., sound input selection), users
are sometimes forced to quit the application, go to the control
panels to make the necessary change, and then launch the application
again. Giving applications access to the AV settings can make these
tasks much less disruptive.
- Create a design that is extendible.
The team is committed to designing and implementing a long-term
solution. To achieve this, the design (in terms of both interaction
and architecture) must provide a place and a means for adding new AV
devices and features.
Above: the main window - as shipped.
This window shows every AV device
that’s currently part of the user’s system. (This happens to be a
very complex AV system.) The user can activate or deactivate a
device by checking or unchecking it in this list or by clicking its
icon in the map view. (The user can also view by list- or map-only.)
The user can access additional settings for the device by
double-clicking it. Buttons below provide access to settings that
affect the entire sound and video systems.
Above: future enhancement for the map view in the main window.
shipped, the map view is not much more than a collection of icons.
In the proposed UI design, the icons were better integrated to
create a more coherent map. Time constraints prevented the
engineering team from implementing this design. Apple Computer has
applied for a design patent on the enhanced map view.
Above: the main window - an early design.
illustrates how the initial concept was presented to the team and to
participants in the first user study.
Above: the AudioVision Input Jack - sensitivity controls
Above: the AudioVision
Input Jack - loopthrough controls
The AudioVision Input Jack window opens when the user
double-clicks the AudioVision sound input jack in the main window.
The window shown above includes all the settings associated with the
sound input jack on an AudioVision 14 display. Because this device
has a relatively large number of settings, they are organized into
two panes of information. (Most devices have fewer settings.) Each
pane is accessed via the button bar at the top. (A screenshot
showing the correct button icons isn’t currently available.)
Above: the Arrange Displays window.
This window allows the user to
arrange the displays (including any TV connected to the Video Output
port) currently connected to the AV system. The displays can be used
to create a single, unbroken desktop (as shown above), or certain
sections of the desktop can be duplicated on more than one display.
The latter feature would, for instance, allow a user making a
presentation to work at a portable computer resting on the podium
and the audience to viewed the work on a big-screen TV behind the