pNothing has been more prolific over the past century than humanmachine interaction. Automobiles, telephones, computers, manufacturing machines, robots, office equipment, machines large and small all affect the very essence of our daily lives. However, this interaction has not always been efficient or easy and has at times turned fairly hazardous. Cognitive Systems Engineering CSE seeks to improve this situation by the careful study of humanmachine interaction as the meaningful behavior of a unified system. pWritten by pioneers in the development of CSE, Joint Cognitive Systems Foundations of Cognitive Systems Engineering offers a principled approach to studying human work with complex technology. The authors use a top-down, functional approach and emphasize a proactive coping perspective on work that overcomes the limitations of the structural human information processing view. They describe a conceptual framework for analysis with concrete theories and methods for joint system modeli