Assessment can be classified into different types and purposes, depending on when, how, and why it is conducted. For example, formative assessment is an ongoing process of gathering and interpreting evidence of student learning during instruction in order to provide feedback and adjust teaching strategies. This type of assessment can include informal methods such as observations, questions, discussions, quizzes, and exit tickets. Summative assessment is a formal process of evaluating student learning at the end of a unit, course, or program to measure achievement and report grades. This type of assessment can include standardized tests, projects, portfolios, essays, and exams. Diagnostic assessment is a process of identifying students' prior knowledge, skills, and misconceptions before instruction to plan appropriate learning activities and interventions. This kind of assessment can include pre-tests, surveys, and interviews. Performance assessment is a process of assessing students' ability to apply their knowledge and skills in authentic or simulated tasks in order to demonstrate their understanding and proficiency. This type of assessment can include demonstrations, presentations, experiments, and simulations. Each type of assessment has its own role and function in the teaching and learning cycle; thus it should be aligned with the intended learning outcomes and standards.