Wizard of Oz Prototyping
In the field of human-computer interaction, the Wizard of Oz (abbr. WoZ) technique is a research experiment used to test a concept/prototype that may not exist yet but appears to be functional because someone is controlling it behind-the-scenes.
How does it work?
The UX Researcher is in one room with a participant who’s interacting with the prototype and in another room, another member of the UX research team is controlling the prototype’s responses. No actual code is involved—just a “man behind the curtain” pulling the levers like the WoZ. In fact, The term Wizard of Oz is clearly inspired by the scene in the movie The Wizard of Oz in which Toto the dog pulls back a curtain to reveal that the wizard is actually a man who is flipping switches and pulling levers.
This method is often used in agile software development and lean programming to improve how business rules are implemented in software. after each interaction, anecdotal feedback and data are gathered and analyzed to help improve the next round of development. The test-and-learn cycle is repeated until development is concluded.
Why does The WoZ matter in UX?
This methodology has a flexible approach that allows concepts to be tested and modified without having to worry about potentially tiresome code changes, breaks in a daily testing schedule, or full development costs. Some of the advantages can be that creating multiple variations is easy, the process is fast (faster) and thus, cheaper and prototypes are more iterative and realistic than paper ones. Moreover, the WoZ methodology places the user at the center of the development process.
What are the disadvantages?
Simulations may misrepresent otherwise imperfect tech. May simulate technologies that do not exist (and may never). Wizards require training and can be inconsistent, it can be exhausting and some features are difficult/impossible to simulate effectively.