Taxonomy vs Taskonomy
In my consulting activities, I often have to explain to companies that they are too logical, too rational. Human behavior seldom follows mathematical logic and reasoning. By the standards of engineers, human behavior can be illogical and irrational. From the standpoint of people, however, their behavior is quite sensible, dictated by the activity being performed, the environment and context, and their higher-level goals. To support real behavior we need activity-centered design.