Last week I was at a seminar where a fellow student was outlining some (very interesting) research about how to adapt 'professional' products to be usable by a 'lay' audience (what functions do you retain, what do you lose, how do you deal with different mental models? and so on) He repeatedly referred to the importance of 'user experience' throughout the presentation, and it took me a while to realise that he was not talking about UX, but "the degree of prior knowledge/understanding a user has, having dealt with similar products/systems". That made a whole lot more sense. Yet no-one else in the room - including a number of people with backgrounds in human-centred design - asked about or pointed out this (quite important) difference.
It made me think: how often in science, technology - indeed any subject - are people talking about very different things yet using the same terminology? Do they realise they're doing it? And can this ever be used as a deliberate provocation tactic to generate new ideas or ways of looking at things? Can we think of third and fourth meanings for terms that might give us insights? (E.g. with 'user experience', can we think of the 'experience' a product has with a user - his or her quirks, errors, misperceptions and so on - rather than the other way round? Is that ever helpful?)