ABSTRACT
While the database of a science grows incrementally, understanding is a far more nonlinear process that is prone to phase transitions (what Kuhn, 1962, called paradigm shifts). As the database grows, the working assumptions of the current paradigm begin to be questioned and new insights and organizations begin to emerge. Throughout this book, we have advocated for an alternative organizing framework or paradigm for thinking about human performance in general and about interface design in particular. It is not really a new perspective since many of the ideas can be traced back to early functionalist psychologists (e.g., James and Dewey) and philosophers (e.g., Peirce). More recently, the practical value of the insights of these early psychologists has been rediscovered by cognitive systems engineers concerned about the functionality of human-machine systems (e.g., Rasmussen and Vicente 1989).
