Mark holds a Master of Science degree in Clinical Language, Speech and Hearing Sciences. He was a lecturer in fluency disorders at Utrecht University of Applied Sciences for nearly 30 years. As a speech and language therapist he has extensive experience in working with persons who stutter. He was involved in the development and implementation of the Dutch "Evidence-based guideline developmental stuttering in children and adults" in cooperation with the CBO Dutch Institute for Healthcare Improvement. He is a member of the European Fluency Specialists board and represents the interests of the Dutch Association of Stuttering Therapy (NVST) in ECSF.