Reading: Universal Methods of Design by Bella Martin and Bruce Hanington.
The Wizard of Oz (WoZ) technique, at it’s core, is a way for testing the feasibility, functionality, and general effectiveness of a UI without requiring all the time and effort into making a prototype. This is done by creating a mock-up interface for the user to ‘use’, where someone(s) on the team (the ‘Wizard(s)’) manually implement the interface. For example, say I wanted to design a smartphone banking app, which has a few functions, and a few different pages. If I wanted to gauge how a customer was feeling about this using WoZ, I may preemptively draw out all the possible pages the user could access on small whiteboards, and when the user ‘clicks’ (in this case, points and tells me “I would like to click this”) on something, I would swap out the whiteboards and adjust any numbers, as needed. The whole point is to get a general sense from the user. ie. “Man, it’s annoying that I cant get from here to there in one click.”