Voice User Interface Design - Purpose and Process

Darla Tucker
Intervoice, Inc.

July 2003

Applies to:
    Microsoft® Speech Technologies

Summary: Learn about essentials for creating a successful speech-enabled calling solution. This article will explore the importance of delivering a voice user interface that is successful in achieving a higher technology standard while delivering a positive user experience. (3 printed pages)

The Purpose of Voice User Interface Design

Today's enterprise organizations have two competing goals: they must provide their customers with a consistently high-level of customer service while simultaneously achieving cost savings. Speech-enabled over-the-phone automation solutions allow enterprises to reach both these goals. However, end-users are becoming increasingly technology savvy, and thus speech-enabled applications must evolve quickly to meet consumer needs. Users expect highly effective, efficient solutions that are likable and quickly learned.

So, how is customer service built into an automated call solution? While the underlying technology is important, the critical goal to focus on is delivering a successful voice user interface (VUI), and the primary objective for any VUI must be creating a positive user experience, for the users of the application. The user experience refers to the overall impression a user has after interacting with an application. Users who have had a positive experience using an automated speech system feel valued by the company deploying the system, and are more likely to continue to do business with such companies in the future.

Creating a voice user interface may appear simple on the surface, but this simplicity hides the rigor and complexity of the process. First and foremost must be a relentless dedication to the goal that the vast majority of callers will hang up the phone feeling good about the service that was provided. Only then will the business goals of revenue generation and cost-savings be fully within reach. This article and the April 19, 2003 MSDN® Webcast entitled Voice User Interface Design: Purpose and Process provides you with a framework for understanding the importance of VUI design as a development activity and demonstrates the crucial steps in the VUI design process.

VUI Design Process

Like all good construction, a successful speech-enabled application is built on a solid foundation. This foundation is composed of three equally important pieces. First are universal user interface guidelines and usability principles. Second are the project guidelines for the application as well as system requirements. Third are the interaction guidelines for the personality that will be portrayed by the VUI. Together, when understood and defined properly, these three pieces will set the stage for achieving success. Each of these areas will be explored briefly below.

Element 1: Universal Design Guidelines

Universal design guidelines are comprised of a set of Principles and Heuristics. Design principles describe the desired interaction attributes that are expected when a communication dialog is started. A well-designed application should represent a conversation with a co-operative and polite person. Heuristics are rules of thumb that have been gleaned from experience and numerous usability evaluations. Applying these heuristics to a design ensures that the basic elements of usability are embodied in the VUI.

Element 2: Project Design Guidelines

Project design guidelines are the critical pieces of foundational information about the business and the caller that must be gathered and analyzed before any scripting takes place. As the designer it is extremely important for you to know who the audience is, what they want, and how they perceive the business and the task at hand. It is equally important to know the business and their strategies and goals. Along with understanding the business and the caller, the base functionality for the application and the underlying business rules that drive or control the application must be gathered. Above all, the most important aspect of the design is making sure an exhaustive definition of the caller population is done. Callers are calling automated systems to solve real world problems. They only want to solve their problem or satisfy their need without being confused by company jargon or unrealistic user demands such as complex menu structures or overloaded prompts. If done correctly, by creating a fundamentally sound design that incorporates these elements, the application won't inhibit the caller and they will accomplish their tasks with ease.

It begins with learning to understand the goals of the user and determining how the application can help them achieve these goals. This tutorial will provide you with practical techniques for moving beyond simple user profiles and delving into the unspoken needs of your users.

Element 3: Interaction Guidelines

Interaction guidelines describe the personality created based on the information gathered and analyzed in the project design guidelines phase. A consistent, well-defined personality will have a direct impact on the caller's impression of the quality and credibility of the system. Personality refers to creating a permanent character, as the voice of the IVR, which interacts with the caller in a two-way conversation. The words that are spoken, the voice that is heard, and the manner with which errors and timeouts are recovered are the embodiment of the personality created to represent the company as one of, if not the most important employee.

Overall Summary

Now that the design foundation has been outlined as the integral part of the process it's extremely important to highlight again the primary focus, which is "Who are the callers, and why are they calling?" You can design a system to fully meet the needs of the business, the functions specified by the business, using the language or internal terminology of the business, and fully designed it to addresses the fundamental business logical behind the process rules. If you do that it will satisfy the needs the business, but possibly not the consumer. Shouldn't that be enough?

Well no, not when the business is ultimately concerned about the bottom line, which is "Am I getting the ROI I expected from this automated solution?" and "is customer service being enhanced?" If we don't strive to serve the caller (our customers' customer), and if we don't provide the caller an easy and enjoyable experience, they won't call back. They might even take their business elsewhere.

The right process starts with getting all the information up front. Then it's analyzed, twisted, turned, ripped open, analyzed again, turned upside down, mashed up and analyzed yet again. This leads to a sound design for an automated call solution when Universal Guidelines, Project Guidelines, and Interaction Guidelines are incorporated into the overall project implementation process.

Positive user experiences are created when applications anticipate the needs and preferences of the user and conform to the user's mental model of the domain and of conversation.

Spending time getting to know the business, the caller, and what each wants, along with a proven foundation for design are the essential keys to the success of speech recognition calling solution.