January/February 2002

Speech Technology Trends:
Move Over "Look and Feel," Make Room for "Persona"

By Jim A. Larson

Every speech application has a persona‹the personality, character, disposition, tone and attitude of the application as it interacts with the user. Verbal games may have a cheerful persona, banking applications are more formal, and applications providing driving directions sound knowledgeable.

Just as the television news program's ratings depend upon its anchor "personality" as much as the news content, an application's appeal may depend on its persona as much as on its content and functions.

In traditional applications with graphical user interfaces (GUI), we used the terms "look and feel" to describe the application's persona. Developers carefully selected and consistently applied fonts, colors, screen layout and wording to give the application the desired look and feel. Voice user interface (VUI) developers need to carefully select wording for prompts and event handling messages, as well as the voice characteristics to define the VUI's persona. A poorly designed persona is a turnoff and distracts the user from performing serious work.

Process for Creating a Persona
Creating a persona has many similarities to creating, casting and acting the leading character in a motion picture film.

1.Identify the audience. The screenplay author first identifies the intended audience. The persona author should also identify the intended audience for the application, and enumerate the application benefits to members of the intended audience.

2.Determine the major theme. The screenplay author determines the film's message. The persona author should also specify what impressions and feelings the application should convey to the audience. In addition to the persona, the application's logo, brand and marketing literature should also convey the theme that supplements a corporate identity.

3.Describe a fictional persona. A persona author should characterize who would make an excellent spokesperson for the application and convey the desired impression to the intended audience. Some persona designers write a short biography of the fictional persona, just as many authors write a short biography for the lead characters in a screenplay. The biography will provide hints to persona developers about how to phrase messages and prompts.

4.Define the wording of each message and prompt. Screenplay authors carefully construct each phrase of the play's dialogue. Persona authors also carefully word each prompt so it conveys the persona's message and personality.

5.Conduct an audition. Compare several synthesized voices or listen to voice actors. Select the voice with the tone, accent and energy that matches the persona's. This is similar to a director casting the key role in a film.

6.Determine the speed, tone, and prosody of each prompt. For synthetic voices, use a speech markup language such as the World Wide Web Consortium's (W3C's) speech synthesis language to encode the voice characteristics. For prerecorded voices, the voice actor emulates the persona when recording the messages and prompts. This is similar to a director's instructions to an actor so that the actor conveys a consistent and convincing personality and message.

7.Audio format the dialogue. Just as sounds and special effects enhance a film, non-verbal sounds, background music and pauses enhance the persona and improve the understandability of prompts and messages.

Some things to consider when designing a persona include the following:

1.Buy vs. build. General Magic patented a dialog development methodology for the creation of voice user interfaces that have a natural conversational style. They provide a service that includes selecting voice talent, voice recording, directing, processing, usability studies, voice personality design and studio production of voice personality. General Magic has developed some very respectable personas, and it may be cost effective to offload persona development to them or to other experienced persona developers. For more information on General Magic's patent, please visit www.generalmagic.com

2.Staffing. Writers and directors have experience creating personas, while most software developers do not. Consider including a writer or director on the design team for verbal applications.

3.Leverage conversational symmetry. Users have a tendency to respond the same way prompts are presented. Short prompts encourage the user to make short responses while long prompts seem to encourage long user responses. The application's persona will determine much of the nature for the user's input. The persona's attitude to the user will result in the user having a similar attitude towards the persona and to the application.

4.Avoid cutesy personalities. Some users love to hate the paper clip, a help icon in Microsoft Windows. It is important to test user's preference for a persona by both initial users (is the persona helpful?) and long-term users (is the persona annoying?).

5.Test, test, and test. Just as corporate brand names and marketing campaigns are tested with potential customers, the persona should be usability tested with the application's intended audience. Answers to specific questions about the user's likes and dislikes of the application will influence persona refinement.

Just as GUIs have benefited from careful and thoughtful look and feel design, VUIs will benefit from a careful and thoughtful persona design. It's not easy to design and implement the right persona, but it will result in greater user acceptance of the voice application.

Dr. Jim Larson, Ph.D., is chairman of the W3C Voice Browser Working Group. He is the author of Developing Speech Applications Using VoiceXML He may be contacted at www.larson-tech.com.