Location Manager

Lisa provided design feedback during Location Manager's concept investigation phase, then became the UI design lead during design development and implementation. As part of the design process, Lisa conducted three rounds of usability testing, one using paper prototypes/Wizard-of-Oz method. The following text is an excerpt from the 55-page "Human Interface Specification" she wrote for this product.

Function

Location Manager (LM) 1.0 allows the user to partially automate reconfiguration of his or her PowerBook in response to a change in physical location. The user configures the PowerBook as desired for a given location, then uses LM to save the current settings under the name of that location. The next time the user returns to the same location, she informs LM of the change in locale. LM then automatically reconfigures the PowerBook to the settings specified for that location.

LM may eventually become a general-purpose mechanism for saving and restoring sets of settings. Its initial and primary purpose, however, is to facilitate location-based reconfiguration. LM 1.0 will therefore include a limited number of settings, all targeted at mobile users:

*This is a new setting introduced in LM. Its functionality is similar to that of the Startup Items folder, except that opening is triggered whenever the user switches locations. This setting will be removed from LM when Maxwell becomes available and this functionality is provided by Assistance.

LM 1.0 is extensible, and a detailed API will be released. From the user’s perspective, additional functionality is added to LM by installing additional LM extensions, with each extension representing a unique setting.

LM 1.0 is a relatively unsophisticated tool for capturing existing system settings. However, LM 2.0 may introduce ghosting, a feature that would allow users to create locations and edit them without affecting the current system settings. With ghosting, users could launch the appropriate UI (e.g., a control panel or the Chooser) from within LM, adjust the pertinent settings, and save the new values in LM without changing the system settings.

Ghosting is a feature that requires rewriting the original UI, so ghosting settings will be rare (maybe non-existent) initially. Over time, such settings are likely to become increasingly common. It was once hoped that the Open Transport 1.5 control panels would be the first ghosting control panels, but this is not currently the plan.

Nevertheless, several important UI requirements have been identified for ghosting settings:

• The ghost UI should resemble the current UI if any exists. (In other words, don’t create a new UI for an existing setting.)
• The ghost UI should allow the user to adjust only those settings that LM actually saves.
• The ghost UI should not allow users to switch to other layers of the Finder (if possible), and closing the ghost UI should return the user directly to LM.

Another important improvement, slated for LM 2.0, is location monitoring, a feature that will allow users to update locations automatically. As the user leaves a location, LM will compare the settings recorded for that location with the current system settings. If LM detects a difference in any of the values, it will notify the user and offer to save the changes.

Design Goals, Objectives, and Rationale

Location Manager provides reconfiguration support for mobile users working in varied settings. The goal of LM is to minimize the number of steps required to reconfigure a PowerBook in response to a change in the user’s physical location. At present, the user must adjust each control panel setting, Chooser option, etc., individually.

LM allows the user to adjust multiple settings in a single step. Walkabout’s intended use is to swap entire sets of settings in a single step. It is not intended to replace other user interface mechanisms that provide quick-access to individual configuration settings (e.g., Control Strip).

As part of our effort to provide maximum ease-of-use, the following design objectives were targeted:

• Help users develop a clear and accurate conceptual model of WA. A clear conceptual model is an invaluable aid to learning and using any tool. The UI should present WA’s functions, operation, and limitations explicitly wherever possible.
• Support a full range of location-sensitive configuration settings. LM will be most useful if it is supports all the settings that a user is likely to update as a result of changing locations.
• Provide users with a quick-access mechanism for switching locations. Even though LM will automate the reconfiguration process, it will be poorly received if the switching mechanism is buried several layers into the Mac UI. Users should be able to initiate automated reconfiguration with minimal effort.
• Build on existing configuration mechanisms wherever possible. Recreating UI mechanisms that already exist would require substantial design and coding effort and might confuse users, who are already familiar with the Chooser and the various control panels.
• Design for future extensibility. While LM 1.0 will include a small number of settings, it will be necessary to add additional settings as functionality and needs change. The UI design must be flexible enough to accommodate growth in functionality.
• Design with the limited screen size of PowerBooks in mind. It is important that each LM dialog occupy as little screen area as possible and that the various dialogs work well together.

Screenshots

Above: the main window of Location Manager 1.0.

This window opens when the application is launched. From here the user can tell the system what the current location is (in this case it's "Home"); create a new location; or open, duplicate or delete the selected location.

Above: the location window.

The "Location Name” field is editable, allowing the user to change the name of the location. When the location window first opens, the "Location Name” field is selected. The Macintosh Guide button is enabled, but all other buttons are disabled.

The "System Settings” list (to the left) contains all the settings that are available for inclusion in any location. The "Settings for this Location” list (to the right) contains the settings that are included in this location. (The "Default" location includes all the available settings except Auto-Open Item.) Items in the "System Settings” list are alphabetized; items in the "Settings for this Location" list appear in the order in which they were added. A bullet (•) next to an item in the "System Settings” list indicates that the setting’s current "System Values" are different from the values saved for the open location. In the example above, the user has adjusted her computer’s sound level so that it is no longer at the value saved for the “Default” location. (More about "Default" location values later.)

Activation is mutually exclusive among the three fields in this window (“Location Name,” “System Settings,” and “Settings for this Location”), and exactly one field is always active. The presence of a black focus ring indicates that a list is active, while text highlighting or the presence of an insertion point indicates that the location name field is active.

Clicking an inactive field activates it and deactivates the others. Clicking elsewhere in the dialog has no effect on activation. Pressing the tab key cycles activation between the three fields (from location Name to "System Settings” to "Settings for this Location" and back to “Location Name”). Tabbing to the “Location Name” field causes its text to be highlighted, as shown above. Shift-tabbing cycles through the fields in reverse direction.

The scrolling lists are single-selection. No System Setting is selected 1) when the location window is first opened (as shown above) or 2) if the user clicks within the list but below the last item. No Location Setting is selected 1) whenever the list is empty, 2) whenever the list is inactive and a System Setting is selected that is not present in the "Settings for this Location" list, or 3) if the user clicks within the list but below the last item. Whenever a list has nothing selected in it, an instructional message (shown above) appears instead of a value string.

The user can move between items inside an active list by pressing the up- and down-arrow keys. The arrow keys are not affected by modifier keys, nor does selection wrap when the user reaches the end of a list. If a list is active but nothing is selected, then pressing the down-arrow key causes the first item in the list to be selected; pressing the up-arrow key causes the last item to be selected. The user can also select any item in an active list by typing the beginning character or characters of its name (i.e., via type selection).

Clicking an item in either list activates the list, selects the item, and causes the setting’s values to be displayed in the group box directly below:

Above: the Location window showing current system and saved values.

Selection in the two scrolling lists is linked: clicking an item in one list causes the same item to be selected in the other list as well, provided the item is present there. Selection of a list item persists even if the list becomes inactive. (In the “Default” location, the "Location Values" are the factory settings with which the Macintosh shipped.)