Glossary
Wizard of Oz testing
What is Wizard of Oz testing?
Wizard of Oz testing uses a person behind the scenes to supply some or all of a prototype's responses. Participants interact with an interface that appears to perform those functions. The name recalls the person behind the curtain.
How it works
The method lets a team examine an interactive concept before building all the underlying technology. Paul and Rosala's 2024 guidance emphasizes a protocol, prepared responses, feasible simulated behavior, and a pilot.
Example
A person could manually prepare recommendations through a prototype meal-planning interface. The test might reveal that users understand the plans but struggle to find ingredients. That would be a useful question for the product team to investigate.
The test would not establish that automation can provide the same quality, speed, or reliability.
Participant understanding
Interpret results in light of what the operator simulated and what participants believed. Where the method uses deception, the cited guidance calls for a debrief so participants receive accurate information and can decide whether to withdraw.
Why it matters
The method can test an experience before all its technology exists. Keep the evidence about that experience separate from claims about a finished system.