In developing the highly useful technologies, knowledge from human factors and ergonomics (HF/E) can be of great use, especially to designers charged with the difficult task of dovetailing humans and machines in complex systems built to navigate sometimes chaotic environments. The role of HF/E in A 3 design remains centered around the goal that A 3 self-action is ideal to provide maximum benefit to humans while increasing the likelihood of task success. This chapter is written between “artificial intelligence (AI) winters,” times of decreased funding of AI technologies, indeed at a time of great optimism and investments in A 3 technologies. It argues that design is key to all A 3 technologies, and that the advent of autonomy which has no need for humans is not only unlikely, but likely undesirable. The chapter endeavors to provide tools from the HF/E literature with which to shape the development of A 3 with respect to our knowledge of human factors.