Nonsul (論述,writing test),one of the test formats of college entrance exams in South Korea, basically means 'writing logically'- to read the given articles and write the answer to the questions. Additionally, it also includes a similar oral test format called 'Gusul(口述,oral test)' which needs logical and immediate interaction.
Nonsul has recently been positioned as one of the three main factors of entrance exams in Korea, which includes 'Haksaengbu(學生簿,GPA)' and 'Sunung(修能,The Korean SAT)' but Nonsul has only been adopted in 20 high-class universities, mostly because of the huge effort and time needed to fairly evaluate the answer sheets.
Usually, there are no official 'Nonsul' classes in regular schools so many students depend on private academies.