The road to science for the arts therapies requires research on the full breadths of the spectrum, from systematic case studies to RCTs. It is important that arts therapists and arts therapeutic researchers reflect on the typical characteristics of each research paradigm, research type and research method and select what is appropriate with regard to the particular research question. Questions rather differ. Finding out whether a certain intervention has a particular effect with a large group of clients differs from wanting to know which change occurs at which moment by which interventions in the treatment of an individual client. Research in practice remains close to questions encountered by arts therapists in their daily practice. It concerns questions arts therapists have about their lived experience of acting due to the complexity and variability of practice. By carrying out research in practice that links up with those questions, evidence evolves; evidence that enables the professional to proceed and that makes explicit what often remains implicit and unsaid. What is explicit can be communicated, can be criticised and tested. The professional himself does the road to science of the profession. The investment in professionals’ research in practice is the motor of knowledge-productivity that bridges the theory-practice gap. Research in the arts therapies should lead to ‘knowledge’ in which the ‘art’, nor the ‘subject’ of therapist and client have been lost.