“For testing stuff hot off the presses, we basically walk around the office with a few prototypes, tackle people to the ground, and force them to use the application. This could either be in the form of static mockups or sketches, coupled with questions like: What do you think will happen if you click this? Or, the process that I find most valuable for an application like this is to create a simplified prototype of the behavior that we’re thinking of and let people have a go on at it.
It’s quite different to have an image that requires people to use their imagination than it is to present them with what the engineers will build after two months. So, I have a bunch of different interactive prototypes that focus on one area each — scrolling, typing, inserting, dragging, and so on. And we’ll tune these until we like what we have and users get the optimal experience. Then we hand it off to the engineers to build it properly.”