The document discusses the top 5 most common mistakes teams make when conducting rapid prototyping. These include: 1) equating prototype testing with usability testing, 2) prototyping the entire solution which can be overwhelming, 3) gathering unreliable feedback through vague questions, 4) testing designs at the last minute which puts "lipstick on a pig", and 5) testing one idea at a time rather than comparing multiple ideas. The presentation provides tips to avoid these mistakes such as focusing prototype testing on specific questions, breaking problems into smaller pieces, asking targeted questions, iterating early and often, and comparing alternative solutions.