Say Pringle!
Sam Cranwell
Sam Cranwell
24th Jul 2017

UX: User testing chat bots before you start coding

It’s becoming harder to avoid the growing number of Voice-user interfaces (VUI) and the variety in their application in our everyday lives.

Here at Versantus, having already created several “conversation bots”, we are firmly in the belief that the right VUI’s in the right scenarios can make interaction with computers easier, less stressful, more accessible and pleasurable, as well as reducing the time & cognitive processes required to perform a task. As a User Experience designer working on any VUI, you need to consider many factors about the interaction, such as: environment, the VUI’s personality and users dialogue. But once you've planned out your possible utterances and responses, how do you go about testing it? That's where the Wizard of Oz comes in...

User testing with “Say Wizard”

You can simulate the experience of interacting with a voice app using a tool called “Say Wizard”, which is free, and allows you to learn a lot about voice app interactions without having to build one for real. This type of testing is called “Wizard of Oz” testing (WOZ), taking it’s name from the 1939 movie, and the Wizard of Oz’s awe inspiring talking machine.

Download Say Wizard

Adding your VUI’s responses

You will need to add all the possible responses your VUI might give into a script file (script.txt). These are the only responses “Say Wizard” can give, and are spoken by the programme after a corresponding letter or number is pressed on the computer keyboard.

Running a WOZ user testing session

For your test you will need at least two UX testers, one to explain the task to the user and take notes - and another to operate the “Say Wizard” programme.

When you brief your user about the VUI, be sure not to tell them how to ask questions, just simply tell them what the app is for. So they’re not just talking into thin air, it’s a good idea to have a prop to represent your voice app, I often use a tube of Pringles as I think it looks like and Amazon Eco and it’s a good ice breaker :) Tell your user how to initiate a conversation with the VUI, such as “Hey Pringle”.

As the user asks questions to the VUI, you as the Wizard press a key to give the best response from your script. If there is no right answer, then there is no best response, but failing gracefully is as important to the user experience as any other feature. Having an “I can’t help you with that” response can be very useful in these situations.

You will probably need to adjust your script after each user testing session, adding new responses or tweaking others. Take notes on everything, including the user's own dialogue. Like in any user test, it can be helpful to video these interactions to share and review later.

At the end of this test, ask some summary questions about how the users felt about the responses and the vocabulary, speed and tone.

Want to know more?

We work with a wide range of businesses, helping them achieve better results by investing in smarter technology. If you’d like to know more about our work with Amazon Echo, Badminton, or Drupal, or if you just want a chat about the latest technology and how it might help you, then call us on 01865 422112 or email

If you enjoyed reading this article we'd suggest you find out how our chatbot technology is helping businesses cope with COVID-19.

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