After that, you reserve some time to ask questions, explain design decisions, and answer the test user's questions. Unobtrusive observation With unobtrusive observation you learn whether people can use your design in an easy and efficient way, and where this is not the case. How people behave and how people explain their behavior are two different things. If you want to learn about behavior, you have to study behavior. If you want to learn whether users can use your design, you have to observe how they use it, not ask them what they think of it.
Opinions are bad predictors of behavior.
During one usability tests we observed that test users were able to complete only 1 out of 5 basic tasks with the system. But when we asked them their opinion afterwards, they told us the system was great. Tips for unobtrusive observation 1. This is actually very hard. It seems to be in our nature to help others when they are in trouble.