For a quick inspection of your voice-based designs, a heuristic evaluation can be used. The most famous one is by Jakob Nielsen. The only issue is that it’s mostly for computer software and not voice designs.
I’ve taken some of the things I look for when evaluating automated phone systems and other voice interactions of Fortune 500 companies, to ensure the system follows best practices and conversational design guidelines.
Here are some of the things you should think about when judging a voice design.
- Does it have natural, conversational sound and dialog flow?
In other words, is it following linguistic principles of spoken language? For example, the use of discourse marker (Now, By the way, etc.), pointer words (that vs this), Grice’s cooperative principles? A hint is that the way we speak is different from the way we write.
- Are the errors progressive and helpful in nature?
When encountering errors, are they helpful to the user? If your voice application is just repeating the same error over and over again, it really doesn’t help the user move forward. A hint here is the more the user fails, the more the errors should guide the user, from general to specific.
- Does it match the user’s mental modal by using customer language and does it meet the expectation around the tasks to be completed?
Is the system being proactive and anticipating the user’s reason for using the application? For example, if I’m using a voice application to check the status of my order, the system should be proactive and look up my account info to see if there’s an active order. When it comes to customer language, are you speaking the way they speak? A hint here would be to avoid technical jargon and use the words of your target audience.
- Right-channel: Voice is not the right channel for everything. So is it leveraging the right channel?
Just because voice interaction is a trend now doesn’t mean it should be used for everything. What’s the context of the usage?
- Does it accommodate frequent users, give personalization and remember what some of the choices or reasons why they’re using the device?
Are you thinking about your power users? Having your frequent users go through every single option every time is not a good way to create a memorable experience. This is something to think about when designing error strategies as well. Giving a personalized greeting and seamless experience will enhance the overall experience of the application.
- Does the persona fit the tasks (i.e, brand perception, demographics, etc.)
Every brand has an image and are you designing with that in mind? Understanding the demographics, target users, frequency of usage can all help with creating a persona that fits right for the tasks.
While voice is still catching up, it’s important to think about how to create a great experience for your users. All these can generate greater task completion and overall customer satisfaction.