Assessment refers to a wide variety of methods that teachers use to conduct in-process evaluations of student comprehension, learning needs, and academic progress during a lesson, unit, or course. Formative assessments help teachers identify concepts that students are struggling to understand, skills they are having difficulty acquiring, or learning standards they have not yet achieved so that adjustments can be made to lessons, instructional techniques, and academic support.

The general goal of formative assessment is to collect detailed information that can be used to improve instruction and student learning while it’s happening. What makes an assessment “formative” is not the design of a test, technique, or self-evaluation, per se, but the way it is used—i.e., to inform in-process teaching and learning modifications.

Formative assessments are commonly contrasted with summative assessments, which are used to evaluate student learning progress and achievement at the conclusion of a specific instructional period—usually at the end of a project, unit, course, semester, program, or school year. In other words, formative assessments are for learning, while summative assessments are of learning. Or as assessment expert Paul Black put it, “When the cook tastes the soup, that’s formative assessment. When the customer tastes the soup, that’s summative assessment.” It should be noted, however, that the distinction between formative and summative is often fuzzy in practice, and educators may hold divergent interpretations of and opinions on the subject.

https://www.edglossary.org/formative-assessment/