This online PhD specialization will help you combine practice with theory and advanced skills in critical thinking, research, and problem solving by deepening your understanding of strategic and tactical issues that are critical to the success of performance improvement interventions. The training and performance improvement curriculum is based on the Human Performance Model developed by the American Society of Training and Development (ASTD). Residency Requirements: As a doctoral learner you will attend residential colloquia in addition to your online courses. Taken during specific milestones in your program, you will attend three colloquia, each one week in length.