Requirements: Sketch a simplified design of your product onto a napkin. Perform user tests using sketch; consider tests failed if users cannot identify product.
UX test results: Users explained thought process behind using a microwave, comparing it to their mental model. Buttons caused confusion; “clever” titles didn’t let the user know function, so the gulf of evaluation could not be bridged. Mappings were illogical; user #2 discussed this when we were testing him. Users made description-similarity slips when encountering the “start”, “time cook”, and “reheat” buttons.
Design implications: Should do away with the majority of the additional function buttons, leaving only “popcorn” and perhaps “reheat” behind. According to users' mental models, it should operate by pushing the desired time and then start. Need to consider the mapping; additional functions should be separate from the number pad. Knowledge in the world should be increased so users will not be confused.