Sivasailam "Thiagi" Thiagarajan makes a living by having fun and helping others have fun. With a PhD in instructional systems and a background in cognitive sciences and social psychology, Thiagi specializes in interactive strategies for improving human performance. An author of more than 20 books and designer of more than 200 published games, Thiagi writes an online newsletter, "Play for Performance." As a global nomad, Thiagi has lived in three different countries and cultures (India, Liberia, and the United States) and has worked as a consultant in 27 other countries.