Dr. Willis has presented papers or empirical research at 16 conferences since 1981 throughout the U.S. on Assessment Center Methodology, including an invited speaker at the IACP annual conference on Assessment Centers in 1996.

Dr. Maher is the author of an internationally recognized and utilized Assessor Training Manual and Training Tape. This material has been purchased and is used by many other consultants and jurisdictions in Canada, Great Britain, Guam, Germany, Japan, Sweden, Australia, and New Zealand, as well as by numerous agencies in the United States.

Dr. Maher has also published 2 books on preparing for participating in an assessment center and on the widely used "Preparing Emergency Simulation Exercises" for Police and Fire Departments.

Dr. Maher has presented over 100 workshops, empirical research papers, and lectures at various conferences throughout the U.S. over the past  23 years.

Dr. Maher’s Doctoral Dissertation which is quoted/referenced frequently in  Personnel Psychology and Assessment Center literature, concerns the minimum number of hours of Assessor training to be proficient. This research included subject matter experts from police, fire, and personnel departments in Florida, California, Illinois, Arizona, and many other states and jurisdictions.