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 product.

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 capabilities.

Potential AV devices include:

Sound input - any sound-producing device, including:

  • microphones
  • CD players
  • video cassette recorders
  • audio cassette players
  • television tuners
  • telephone connections

Sound output - any sound-receiving device, including:

  • speakers
  • headphones
  • video cassette recorders
  • audio cassette recorders

Video input - any video-producing device, including:

  • video cameras
  • video cassette recorders
  • television tuners

Video output - any video-receiving device, including:

  • monitors
  • television sets
  • video cassette recorders

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.
  • Create 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.
  • Avoid 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 devices.
  • 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.
  • Allow 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 burden.
  • 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.
  • Develop 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.
  • Allow 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.

As 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.

This screenshot 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 presenter.