The Value of Usability Testing for Speech-Enabled Applications

In an increasingly automated world, speech-enabled applications and services are often touted as a way for companies to provide a human touch in customer service without employing live agents. However, to be successful, automated speech applications must evolve quickly to meet the needs of consumers who expect highly effective, efficient solutions that are likable and quickly learned. Usability testing is a method for evaluating the quality of the caller experience for speech-enabled applications. It reveals diagnostic information on how to improve the application to better satisfy customers. Usability testing offers the opportunity to identify and eliminate problems within speech applications before unveiling them to the public, resulting in time and cost savings for enterprises deploying such applications. As a result, customers are satisfied using the application and call center costs are thereby reduced.

Users Determine Usability
Usability is not a single quality per se, but rather the combination of several factors, including learnability, effectiveness and user satisfaction. Speech applications can, and should, be designed with the needs of the end-user firmly in mind. However, the guarantee of usability cannot be assumed -- it is a property that must be assessed by having representative users interact with each application built. Usability testing ensures that voice user interface (VUI) designs are on target and allow callers to accomplish their tasks with ease and efficiency. According to Gartner, "the most influential factor determining call completion rates is the amount of effort that the enterprise puts into designing, maintaining and promoting its self-service application. Well-designed applications encourage and facilitate use." * Poor usability of speech applications has a direct cost. Every caller who cannot reach his goals using the application will likely be transferred to a live representative. The true value of automated applications is that they handle routine tasks, thus reducing the volume and duration of calls that must be handled by representatives. Poor usability negates this value. Highly usable applications, on the other hand, can build brand loyalty and foster positive relationships with customers by anticipating and meeting their needs.

Voice is a Natural Mode of Interaction
Usability testing has well recognized benefits in traditional software and web domains, such as easier access to needed features, reduced error rates and increased user satisfaction. Usability testing has not yet become a standard part of voice user interface design, although it may provide even greater benefits for speech-based interfaces. This is because callers bring a large set of expectations about spoken language into their interactions with speech applications. More than graphical user interfaces (GUIs) or touch-tone, people expect VUIs to carry on conversations the way humans do. Speech interfaces seem deceptively simple because we all have vast experience using spoken language. Thus when a VUI violates the caller's expectations about conversation, the negative impact can be significant.

Usability Testing as a Market Differentiator
When usability testing is conducted early in the design lifecycle, implementing changes based on the results of testing requires far less time and money than making modifications in response to customer complaints once an application has been deployed. Speech usability testing helps to eliminate problems before customers ever use the application, thus allowing them to interact with applications that are clear, concise, friendly, intelligent, appropriate and honest. If an automated application possesses these qualities, callers will believe that the company values them as customers. Improved usability can be a market differentiator because usable applications increase callers' comfort and confidence levels, are perceived as friendly and trustworthy, and promote brand loyalty.

Dr. Susan L. Hura is a senior staff engineer for Voice User Interface at Intervoice-Brite. She can be reached at mailto:susan.hura@intervoice.com.

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