He held a Ph.D. degree in psychology and learning theory and was co-founder,[2] President and CEO of Interactive Drama Inc. (IDI).
He held a faculty position at the Union for Experimenting Colleges and Universities, where accredited doctorate degrees are awarded from a multidisciplinary, experientially based curriculum.
In the early 1960s, while a professor at the University of Illinois School of Medicine in Chicago, he developed the first natural language computer patient simulation model.
Harless was awarded a second patent in 1998 for his dynamic prompting system used in the virtual dialogue programs.
He published over fifty articles on natural language interactive simulation as a learning strategy, the most recent being the results of a study of the effectiveness of the Virtual Conversations Arabic Language Series.