1. Keying codes, such as airport codes when making a flight reservation, instead
of whole words on entry screens. Codes are also keyed when using a commandlanguage
interface, such as a two-letter state postal abbreviation. On a GUI
screen, the codes may be entered by selecting descriptions of the codes from a
pull-down list of available options. This helps to ensure accuracy, since the
code is stored as a value of the drop-down list, as well as helping to provide
meaningful communication since descriptions that are familiar to the user
are selected. An example would be selecting a Canadian province and having
the two-character postal code stored.
2. Entering only data that are not already stored on files. For example, when
changing or deleting item records, only the item number should be entered.
The computer responds by displaying descriptive information that is currently
stored on the item file. Another example is when a user logs on to a Web site,
the userID is used to find related records, such as a customer record, outstanding
bills, orders, and so on.
3. Supplying the editing characters (for example, slashes as date field separators).
Users should not have to enter formatting characters such as leading
zeros, commas, or a decimal point when entering a dollar amount; nor should
they have to enter slashes or hyphens when entering a date. In general,Web
sites are an exception to this rule, since Web forms do not include slashes or
decimal points. Some Web forms use a series of entry fields with editing characters
between them, such as parentheses around an area code.
4. Using default values for fields on entry screens. Defaults are used when a user
enters the same value in a screen field for the majority of the records being
processed. The value is displayed, and the user may press the Enter key to
accept the default or overtype the default value with a new one. GUIs may
contain check boxes and radio buttons that are selected when a Web form or
dialog box opens. Context-sensitive menus appear when an object is clicked
with the right mouse button. These menus contain options specific for the
object under the mouse.
5. Designing an inquiry (or change or delete) program so that the user needs to
enter only the first few characters of a name or item description. The program
displays a list of all matching names, and, when the user chooses one, the
matching record is displayed.
6. Providing keystrokes for selecting pull-down menu options. Often, these
options are selected using a mouse, followed by keying. Users must move their
hands from the keyboard to the mouse and back. As users become familiar
with the system, shortcut keystrokes provide a faster method for manipulating
the pull-down menus, because both hands remain on the keyboard. This helps
users become efficient at their tasks.On a PC, keystrokes usually involve pressing
a function key or the Alt key followed by a letter. Figure 14.15 is an example
of nested pull-down menus with shortcut keys from Microsoft Visio
Professional. Notice that the user, who is creating a structure chart, can get
into a series of ever more specific menus.
7. Use radio buttons and drop-down lists to control displays of new Web pages
or to change Web forms. For example, when a radio button is clicked, a dropdown
list may change to reflect the radio button choice.A radio button may be
clicked and a form may change according to the choice.A drop-down list may
change or a radio button may be clicked to move to a new Web page. Dropdown
lists are often provided on a Web page for quick navigation, selecting a
new Web page from the drop-down list takes the viewer to that page.
8. Provide cursor control for Web forms and other displays so that the cursor
moves to the next field when the right number of characters has been entered.
An example would be when a user enters an area code for a telephone number,
and, following the entry of three characters, the cursor then moves to the