I think both in the lay person, as you say, it will be more immediately obvious what a computer's doing if you have a visual display, but even in the scientific approaches then I think the ability to present graphical information rapidly and change erm the function that you're looking at is also very important and, for instance in the teaching that we do here, then one of the things that we're very keen on is using computes to show graphically sort of functions that you meet in mathematics and physics.