Consistent User Input Options and Instructions Across Multiple User Interfaces
Many Web developers use XML to represent data and a transformation language, such as XSLT, ASP, or ColdFusion, to transform the XML data to an HTML user interface. Developers change the values of the XML data without having to manually recode the HTML user interface.
Transformation languages can also convert XML data into different user interfaces for access by users with different devices. Developers can use a transformation language to extract and reformat XML data to HTML for publishing on the Web, to Word or PDF for printing, to VoiceXML 2.0 for telephone access, and to a combination of HTML, and either SALT or X+V for multimodal access.
Suppose a user needs to specify the color of a T-shirt that he or she is ordering. The developer specifies the color options, instructions for choosing the color, and other explanations once in the XML schema. The transformation processor then extracts the information and automatically inserts it into each verbal, visual, and multimodal user interface.
Specifying meta information and using mapping languages to construct each user interface has the following advantages:
- Consistent input options. The user always selects from the same input options. The verbal grammar has the same options as the visual pull-down menu.
- Consistent help instructions. The verbal instructions and help messages are consistent with the visual labels and alert messages.
By specifying user input options and instructions once and transforming those options and instructions for each user interface, developers minimize manual changes to the user interface and provide consistent user instructions, options, and help messages across multiple user interfaces.
Figure 3. Use of meta information in visual and verbal user interfaces
Use in visual user interface
Use in verbal user interface
Label of pull down menu
Initial verbal prompt
Which color? For example, Blue
(not used in visual user interface)
Secondary prompt if user fails to respond appropriately to verbal prompt
We need the color to manufacture the right T-shirt for your order
Alert message displayed when the user presses the "Why" button
Response when the user speaks "Why?"
Blue, gray, green, and red
Pull down menu choices
Grammar for user response to verbal menu
Dr. James A. Larson is manager, advanced human input/output, Intel, and author of the home study course VoiceXMLGuide, http://www.vxmlguide.com. He can be reached at firstname.lastname@example.org.