David Clough recently retired after a 43-year career on the chemical engineering faculty at the University of Colorado in Boulder. His prior industrial experience with DuPont, his academic research and consulting activities have been in the fields of instrumentation, process control, computing and applied statistics. Dr. Clough has taught short courses for the AIChE since 1989, including over 120 in-person offerings of Spreadsheet Problem-Solving for Chemical Engineers, and he currently has two on-line courses in the AIChE Academy.