In countries like the United States and the United Kingdom , essays have become a major part of a formal education in the form of free response questions. Secondary students in these countries are taught structured essay formats to improve their writing skills, and essays are often used by universities in these countries in selecting applicants ( see admissions essay ). In both secondary and tertiary education, essays are used to judge the mastery and comprehension of the material. Students are asked to explain, comment on, or assess a topic of study in the form of an essay. In some courses, university students must complete one or more essays over several weeks or months. In addition, in fields such as the humanities and social sciences, [ citation needed ] mid-term and end of term examinations often require students to write a short essay in two or three hours.