HE: Flexibility and Efficiency of Use(提供灵活和高效的使用方式

HE: Flexibility and Efficiency of Use(提供灵活和高效的使用方式 )

Provide Keyboard Shortcuts（需要提供快捷键 ）

Keyboard shortcuts provide alternative ways of issuing commands, and in most cases, using a keyboard shortcut is faster than using the mouse. Using the mouse requires moving the hand from the keyboard to the mouse, moving the mouse to the target, clicking the target, and then moving the hand back to the keyboard. In contrast, when a user uses a keyboard shortcut, their hands need not leave the keyboard.

Examples of keyboard shortcuts:

• On the Macintosh, when a choice of buttons is presented, the button outlined in bold can be "pressed" by hitting the RETURN key.

• Common commands like opening and closing documents in an application, printing, saving, and quitting can be issued using keyboard shortcuts such as CTRL-O (under Windows) or Command-O (under MacOS).

• Windows 95/NT/98 provides an additional keyboard shortcut mechanism. The underlined letter of a menu item indicates that that menu option can be invoked by hitting the ALT key and the underlined letter together. For example, opening a file can be accomplished by hitting the F key and then the O key while holding down the ALT key - or simply by pressing CTRL-O.

Allow for Customization（为专家级用户提供定制功能 ）

Giving users control over how their computer looks and behaves allows users to tailor their environment to suit their preferences. This gives users a sense of being in charge that has an overall positive effect on their experience. It also allows users with special needs to adapt their computing environment to meet their needs. For example, a user with difficulty using their left hand can move important keyboard shortcuts to the right side of the keyboard. Some other examples are

• Speed : Power users want to maximize speed, typically by adding keyboard shortcuts in order to reduce the amount of time they use the mouse.

• Appearance : Some people are strongly affected by the amount of clutter on their screen. Giving users control over secondary menus and toolbars within an application as well as icon placement on the background gives users control over how their computer looks.

• Readability : Other users (such as elderly users) may require a large font for readability reasons or reverse-video (white text on a black background) to reduce eyestrain. Giving users control over the computer’s background, font face and size, and other display settings allows users to adapt these according to their needs and preferences.

 

Example UAR: Button Accelerators Exist

UAR Identifier

HE9 - Good Feature

Succinct description:

"OK" and "Apply" buttons have keyboard shortcuts.

Evidence for the aspect:

Heuristic: Flexibility and efficiency of use: keyboard accelerators.

Interface aspect:

The buttons at the bottom of the screen labeled "OK" and "Apply" have keyboard accelerators, as shown in the picture below. The "OK" button is in focus, so pressing the ENTER key will activate that command. And, notice that the "Apply" button has a keyboard shortcut: typing ALT-A (as indicated by the underlined "A " in "A pply") will activate that command.
 

Explanation of the aspect:

OK and Apply are the actions the users will most frequently want to take (assuming that Cancel is used only for undoing errors and changing courses of action - both of which should be relatively rare in comparison to other actions people choose and carry out.)

The OK button is the default, indicated in the standard way (with a bold outline). The Apply button can be activated by typing ALT-A, also indicated in the standard way: by underlining the "A " in "A pply". Both of these interaction techniques can be found in the Design Guide. (See the following sections in Chapter 8: "Characteristics of Secondary Windows/Default Buttons" and "Characteristics of Secondary Windows/Navigation in Secondary Windows" respectively.)

Benefit of the good feature:

Users who are skilled at using Windows will be able to operate these two commands without their hands leaving the keyboard (which is faster than using the mouse - see "1.1.3 Basic Psychology Needed for Interface Design"). Since the commands are indicated visually in standard ways, skilled users will see these indications and know them for what they are - clues to the keyboard shortcuts.

Solution/Discussion:

I cannot think of any drawbacks to using the standard button labels and actions at this time.

Relationship to other UARs:

None when this UAR was originally written.