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Getting Started With Voice User Interface Design

5 minute read
Phil Britt avatar
Voice interactions can provide richer experiences for customers or be a source for frustration. Some tips on designing VUIs that work.

Improvements in speech recognition in recent years have pushed voice user interfaces into the contact center. But for voice interactions to truly provide better CX than staying with touchtone options, there are a few best practices to follow.

Ask: How Will Voice Experiences Help Your Customers?

“It’s easy to get caught up in conversational AI and all the promises new technologies bring to make the process simpler,” said Eduardo Olvera, senior conversational designer for Nuance Communications. “But organizations must cut through the noise and shiny objects to understand first and foremost the value their conversational experience is going to provide customers and their business.” 

He recommends taking a three-step approach in designing a voice-based user interface:

  1. Identify the customer problem or goal. Decide the problem what you are trying to solve, then design the voice interface to handle those issues. For example, customers may be constantly escalating to your agents for answers to simple questions, ramping up your contact center costs. So include answers to these questions. If, on the other hand, customers are expecting personalized service and advice that can’t be answered via voice (financial services, for example, strictly limit advice from anything but a licensed individual), design the voice interface to escalate quickly to a human.
  2. Apply relevant conversational design strategies. With the problem identified, the next step is to look at it from the lens of conversational design strategies to find the one(s) that will help you solve it.
  3. Find the technologies and services that enable those strategies. Not all voice interfaces are the same. Some include natural language understanding, enabling the customer to ask questions in different ways, rather than sticking to strictly defined wording.

“Those strategies will help guide the way you design, provision, implement and optimize the solution,” Olvera said.

Related Article:Conversational AI Needs Conversational Design

Ask: Do We Really Need Voice Here?

Companies developing a voice user interface (VUI) should start by “speechifying” fundamentals, said Donna Fluss, founder and president of DMG Consulting LLC, a provider of contact center and analytics research firm.

However, some companies go too far with the fundamentals, forcing customers to use voice when touchtone entry would be easier. So rather than “say one for product orders,” the VUI should be enabled to respond, “say or press one for product orders,” for example.

From there, the VUI should be designed with a specific industry in mind, according to Fluss. Customers calling financial services, health care and consumer goods companies all have different needs, so the VUIs need to be designed differently, Fluss said. “Hire someone who designs VUIs within that industry.”

Related Article: Calling All Linguists: The Messaging Bots Need Help

Learning Opportunities

Set Real Expectations of What the Voice User Interface Can Do

Voice user interfaces are very different from graphical user interfaces — you cannot apply the same design guidelines, according to an Interaction Design Foundation blog. “In voice user interfaces, you cannot create visual affordances. Consequently, looking at one, users will have no clear indications of what the interface can do or what their options are. At the same time, users are unsure of what they can expect from voice interaction, because we normally associate voice with communication with other people rather than with technology.”

So the IVA should inform users — bank customers for example — they can obtain balance information, the last five transactions, pay bills, make a transfer, etc., but for other requests the user should ask for an agent. That way, the end user’s expectations are set at the beginning, so he or she knows immediately if they can stay with the IVA or should ask for an agent right away, according to the Interaction Design Foundation.

However, the Foundation also recommended that any list of capabilities or options be kept relatively short, even if the IVA can perform more tasks. In those instances, provide a short list with the option to press a button for additional options.

Related Article: How to Make Conversational AI Smarter

Anticipate Full Conversations, Not One-Time Transactions

In her book, "Designing Voice User Interfaces: Principles of Conversational Experiences," author Cathy Pearl stresses designing interactions that resemble the natural arc of conversations, in other words, interactions that extend beyond one exchange. "Imagine what users might want want to do next. Don't force them to take another turn, but anticipate it and allow it." She also stresses designing systems for sustainable interactions, by keeping all recent history to help the system understand the context of further requests. Part of this is also understanding when the VUI should go into what Pearl describes as command-and-control mode and when it should err on the side of conversational mode. The former alerts the system when the end user is about to speak (e.g. "OK, Google"), the latter lives up to the "conversational" moniker, meaning the user does not need to formally alert the system they are about to ask a question, signaling the system should stay alert longer in anticipation of a prolonged dialogue.

When getting started with VUI design, Pearl recommends starting with creating sample dialogs for five common scenarios your VUI will face. While she admits the approach is rather low-tech, she suggests it is a good way to start understanding how the user experience will play out and also will act as an easily-understandable way to get stakeholders interested. By sprinkling conversational markers into the dialog, the VUI can provide the end user with clear indications of how the interaction is going.