Everyone has their reasons... I particularly like the way Liya Zheng, an interaction designer at Liquidnet and a member of IxDA in New York, describes the reason why her team is interested in mental models. She says, "The most attractive thing is this format for a knowledge repository about our users - unlike scenarios it's not at the solution level so many teams can use it; unlike research notes, it's a way more organized, it gives us the whole picture, and it's organized in a way we visualize data. We can grow it over time and keep track of our innovation space." I just wanted to share Liya's words, in case anyone is looking for reasons to explain why to make a mental model.