In many ways, the most creative challenging and under-appreciated aspect of interaction design is evaluating designs with people. The insights that you’ll get from testing designs with people can help you get new ideas, make changes, decide wisely and fix bugs. One reason I think design is such an interesting field is its relationship to truth and objectivity. I find design so incredibly fascinating because we can say more in response to a question like: “ How can we measure success ?” than “It’s just personal preference” or “Whatever feels right.” At the same time the answers are more complex and more open-ended, more subjective and require more wisdom than just a number like 7 or 3. One of the things that we’re going to learn is the different kinds of knowledge that you can get out of different kinds of methods. Why evaluate designs with people? Why learn about how people use interactive systems? One major reason for this is that it can be difficul...