Wizard of Oz prototyping is a usability method where a user interacts with a non working interface prototype being controlled by a ‘wizard’ sitting in a back room (like the ‘Mechanical Turk’). The wizard observes and reacts on the user’s actions and simulates the system’s responses to the user’s actions.
Wizard of Oz prototyping is usually conducted when you do not have a working prototype or where the findings from the Wizard of Oz prototyping test are basis for designing the system itself (e.g. syntax for voice controls).
On the other hand, digital prototyping is the technically advanced version of Wizard of Oz prototyping, where many of the reactions from the user’s behavior are executed by the prototype itself. Meaning: you already have a digital (interface) prototype which – to the user – seems to work like the finished website/interface, but instead just delivering screen content without any logic in the back end.
When to use Wizard of Oz prototyping?
Wizard of Oz prototyping should be applied when you need to find out specific user behavior to develop the device you are testing itself. Sounds contradictory? Okay, here’s an example: When you want to develop a voice control module for an application, you need the syntax people use to interact with the device. Faced with that problem, you can hardly build a functioning prototype to find out how people use your application. You will need the data itself before writing your algorithms.
When faced only with cursor interactions (and form field input) in an interface, you can apply digital prototyping to get the wanted findings. Create a clickable wireframe that simulates the interaction processes – but without any logic in the background. Now the user can click through the prototype and you can track and observe user behavior.
Where Wizard of Oz prototyping and digital prototyping are connected is, when you find issues where all test users stumble in your digital prototype, you can instantly (at least with some wireframing software solutions) change the prototype to meet user behavior and improve usability on the fly.
How is Wizard of Oz prototyping conducted?
Having a non functioning interface prototype, the wizard needs to see what the user does, since he has to react on user behavior and deliver appropriate output. Therefore the wizard will typically watch video feeds pointing to the test users hands and screen. Now observing an action, the wizard can now simulate the effects of the observed interactions.
To enhance the reality of the test situation, the test users are most often unaware (until after the test session) that they were interacting with a Mechanical Turk.
This, of course, requires a quick reaction and a lot of knowledge about the system on side of the wizard. He hast to quickly and accurately figure out the user’s input and deliver the relevant results in real time.
What you get from Wizard of Oz and digital prototyping?
As seen both usability testing methods have their unique range of use, whereas digital prototyping will probably be preferred, since it does not require an advanced technical setup or observation technology – and no human wizard playing the machine’s brain in some back room.Tags: digital prototyping, interface prototype, mechanical turk, usability methods, wizard of oz