The term 'assessment' usually refers to the process of allotting a quantitative value to students' achievements. Key Points Diagnostic assessment is an assessment made before the learning of a unit commences in order to determine what a student does and does not know about a topic. This form of assessment helps to identify where your students are in their learning and what course of action is appropriate to the learning levels of the students are needed to be taken for continuing or improving their learning. Formative assessment is an assessment through which you can gather data during the learning process when the class progresses through a unit of study to determine a student’s knowledge and skills, including learning gaps. Thus, it is concluded that a teacher uses diagnostic and formative methods of evaluation to identify the problem areas of students in the learning process. Additional Information Summative assessment is conducted at the end of a course or a unit of a course. It does not provide feedback instead it provides the overall results of the teaching-learning process. Placement assessment is conducted before the organization of teaching-learning activities to measure the entry behavior or previous knowledge of the learners.