Educational assessment is used to evaluate student learning and teaching effectiveness. It involves measuring knowledge, skills, attitudes and beliefs. Assessment provides data to guide instructional improvements and motivate learning. It is used for student selection, certification that standards are met, describing student performance, and improving teaching. There are three main types of assessment: diagnostic to identify gaps, formative for ongoing feedback, and summative to evaluate learning outcomes. Effective assessment reflects educational values and is ongoing rather than episodic.