System Architecture - Page 2
November 8, 2001
The figure on the left is a block diagram showing the existing
components of the system, and the relationships to the new
XML/XSLT system required to implement the voice interface.
This drawing is not complete in all areas. For example, no method
for user login and authentication is given, because such a system
would already exist for an e-commerce site, and because although
XML/XSLT would be helpful for creating device-specific login
code, we are not going to examine on- the-fly transformation
(inside a web server, for example) in this particular study.
Designing a Voice Interface
With these rather vague requirements in mind, we can make some
design decisions, and sketch out a rough model for the voice
interactivity envisaged. The goal is to make the experience
simple and intuitive.
- There will be a main menu of options. This is the entry point
to the application, and the user can always return to it with a
single voice command.
- Online help will always be available. This will use the
VoiceXML tag to simplify implementation, and also to
overload any built-in help that may be offered by the voice
platform.
- The number of available options from the main menu should be
kept to a minimum. The total number of states should also be
minimized. This means that the behavior of the current command
should not depend on what the previous command issued was. For
example, the word "menu" should always refer to the main menu in
every context.
- The top-level commands from the main menu should always be
active. If the main menu offers the command "foo", the user
should be able to say "foo" at any point in later dialogs with
the same result.
The following state diagram illustrates these design goals. The
main options are "order status", "product list" (with a link to
voice ordering via the existing phone service bureau), and "more
information" to access a frequently asked questions list. For a
more detailed examination of the issues to consider when
designing voice applications, refer to Chapter 6. The order
status menu leads to a variable number of additional choices,
depending on the number of records in the user's order history.
VoiceXML with XSLT (HTML and WML)
Early Adopter VoiceXML
Creating a Markup Language - Page 3
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