Various assessment tools and their relevance in the Ghanaian context will be introduced. Assessment tools for personality, cognition, emotions and behaviours in both children and adults will be introduced. The rationale for the use of such tools will be discussed. It will also introduce trainees to principles of case formulation and treatment strategies. Application of psychological theories and models of human development across the lifespan will be the focus in case formulation. Emphasis will be placed on evidence-based formulation.