What is an Internal Assessment (IA)? How does it differ from an External Assessment?

Each IB class has an IA which must be completed before the student can receive a mark (1-7) from IBO for the course. For example, the IA in a spoken Language B is an oral presentation with the classroom teacher present and counts 30% of the student's mark. The IA gives the classroom teacher input into the student's final mark for the class. The IB Programme is different from any other program in the world because of the requirements of the IA (teacher input), the Theory of Knowledge course, the Extended Essay, and the CAS (creativity, action, and service) requirements. The External Assessments take place between April 29 and May 25 each year; they are written and graded by examiners located throughout the world.