Design Guidelines for Interactive Voice Response Systems

Given the increasing use of IVR systems as a primary communications channel for businesses to interact with their customers, it is critical that these systems be as easy-to-use as possible.

Today, many companies are trying to rapidly deploy wireless information systems to meet the needs of users who desire access to their data when they're away from their desktop computers. These companies, for the most part, are concentrating on deploying information solutions targeted for handheld, graphics-based wireless devices (i.e., mobile phones, PDAs, or newer mobile phones that double as PDAs).

Unfortunately, because wireless data access is still a relatively new area of technology, service providers and device manufacturers are out to stake their claim to fame (and profits) by introducing proprietary systems. The resulting mess of incompatible devices and services is enough to frustrate even the most savvy users.

However, if these companies were to ever realize that users are seeking information, and not necessarily new technology, they might consider deploying an Interactive Voice Response (IVR) System. As a means to quickly provide information to users on the go, IVRs, if properly designed, can be just as effective as a graphical, device-based "mobile" solution.

The IVR Market Outlook

A report released in June, 2002 by In-Stat/MDR entitled Press "1" for Industry Revolution! 2001 IVR Market Shares and 2002-2006 Market Forecast, examined the current and future markets for IVR products as well as the market drivers and hurdles for IVR. Among other notable findings, the report states that the IVR market is currently going through the biggest change in its history - revolutions in technology are dramatically changing where and how IVR systems are used and advances in speech recognition are further broadening the scope of potential applications.

The report also discusses how Voice eXtensible Markup Language (VoiceXML) is opening the door to building increasingly more and more custom applications. Examples include: Customer help services in Call Centers, Enterprise-wide data availability services, and as general consumer information sources in just about any industry.

Given the increasing importance of IVR systems and the role they stand to play as a primary communications channel for businesses to interact with their customers, it is of critical importance to business success that these systems be as easy-to-use as possible.

Therefore, this article provides a list of quick-hit guidelines for designing effective voice-based system interfaces. Note that many of these guidelines have been adapted, with a little minor tweaking, from User-Centered Design principles that guide the creation of more visual user interfaces.

Menu Structure

• Strive to keep the number menu items to a maximum of 5. Because people cannot actually see the menu items, they have to work to remember the items in the list.
• Place the most frequently used menu items at the beginning of the list.
• If you're using a keypress action as an input mechanism, do not skip numbers (i.e., do not do the following: "For Option A, press 1, for Option B, press 3"). People expect that the menu items will be sequential.
• If you're using a keypress action as an input mechanism, make sure there is an appropriate pause between menu items and between different menus. A person with a cell phone must constantly move the phone away from her ear in order to press the correct key.
• Use silence to convey structure to users but be careful of too much silence, users may think the system is no longer operating.
• The number key needed to activate a particular menu items should follow the text-description of the item itself. Therefore, menus items should be heard as: "To hear our product descriptions, press or say 1" instead of "Press 1 to...." This reduces users' dependence on short-term memory.

Language

• Use short, concise phrases for menu items and other prompts. This will encourage users to keep their responses short, as well.
• Allow users, if the system architecture allows it, to use natural language to choose options. For example, if your prompt is "To hear billing options, press or say 1," structure your system design to be able to handle the situation in which the user might reply "billing."
• Anticipate the use of colloquialisms (e.g., "yes," "yep," "yup," "yeah,") in users' responses, but avoid the use of too many colloquialisms on the part of the system. Research has not shown that a more "human" set of system prompts is more effective and users may in fact grow tired of it quickly.
• Avoid prompts that sound too similar.
• Keep syntax and semantics consistent across all prompts in the system.
• Present voice prompts in the user's language, using a friendly tone. Avoid the use of technical terms, unfamiliar acronyms, and the like for general purpose systems.
• If an error occurs, tell the user what the error was and explain in more detail what type of correct input is expected.

Navigation

• At the very beginning of the application, users should be given instructions on how to navigate the system and which keys are reserved for special functions (i.e., "For Help, press 9")
• Always allow users to select items using either a keypress or voice commands.
• Allow users to select an option at any time. Do not force someone to listen to an entire menu before she can make a selection.
• Always provide some default options that are used consistently throughout the application. Always give the user a way to repeat a menu/spoken item, return to the main menu, access the "Help" functionality, and to speak with an actual human operator (usually, this is the "0" key).
• Verbally confirm user choices so that s/he can be confident about what is happening and that the system correctly "understood" the input.

A voice-based system is available to anyone, anytime, anywhere in the world, as long as they have phone (cell or wired) access.

As such, an Interactive Voice Response System can be a powerful, useful addition to a suite of data-access methods for your business, provided it's well-designed. So as with any system design effort, consult your users about what they need and understand their goals and how they work, first. Then test and evaluate the design early and often.

You'd be surprised at how effective a voice-based system can be at providing "mobile" data access, today, while the device-based market sorts itself out.

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For more information on VoiceXML, please visit VoiceXML.org