From the time of my post-doctoral work at Imperial College, the main focus of my research has been human-computer interaction. Work in this area includes the MINNIE cad system, the invention of the bifocal display, the development of the Lean Cuisine notation for the description and design of direct manipulation interfaces, techniques for the evaluation of interfaces, and more recently the study of CSCW systems. I have associated interests in techniques for information representation and interacting with information, and in computer graphics and image processing