The final phase of training includes 80 hours of supervision, 50 of which can be group supervision, at least 30 of which must be individual supervision. In group supervision, at least one of every 5 hours must be a presentation of the candidate´s own case material. Candidates should choose at least two different supervisors, who must be Teaching Members of ISST. The individual supervisors can not be the personal sandplay therapist. After supervision is completed, a final case study must be submitted and read by three readers for certification. The candidate chooses a training advisor who accompanies her/him along the last phases of certification.