An outcome of international conferences on the professional practice doctorate has been a continuing conversation amongst scholarly practitioners focused on addressing challenges and issues being encountered concerning in the number and variety of professional practice doctorates in the twenty-first century. These conversations have resulted in a proliferation of programs utilizing a variety of pedagogical models focused on practicing professionals undertaking research and development in the workplace. Grounded by critical friend theory, contributions from scholar practitioners in Australia, Canada, England, Ireland, Israel, New Zealand, USA, and Wales address trends and themes in international professional practice doctoral programs. These include how knowledge is produced, organized, developed and used; doctoral program design; program capstone models; insider- outsider collaborative research partnerships; and collaborative ways to work across national boundaries in different settings.