This book aims at finding out the self-perceived competencies that teacher trainees and beginning teachers acquired as a result of the impact that practicum supervision and mentorship have had on them. The stratified proportional and simple random sampling were used to select subjects with 199 second year and 196 third year students and 50 beginning teachers were selected from 5 teacher training colleges and 24 basic schools in the Volta and Central Regions of Ghana. The book also shows that there is a statistically significant difference in the self perceived competence of the three cohorts of second year students, third year students and beginning teachers as a result of practicum supervision and mentorship practices. The said difference favoured those exposed to traditional practicum supervision on off-campus basis at the expense of those exposed to mentorship on on-campus basis. This book recommends that the Ghana Education Service (GES) should ensure that the policy guidelines on the IN-IN-OUT programme are properly implemented to guide practicum supervision in Ghana. It recommends further that the focus during the out period should be on clinical supervision.