The South Korean Education Ministry’s decision to exclude the high-level “killer questions” from the Suneung, the state-administered college entrance exam, has once again rekindled debate regarding the test’s difficulty.

Arguably one of the toughest exams in the world, Korea’s College Scholastic Ability Test, commonly known as the Suneung, has played a pivotal role for decades in measuring students’ potential achievement in the future after enrolling in college and determining students’ learning abilities after 12 years of schooling. The exam was first introduced in 1994 to replace the College Entrance Strength Test in response to criticism that it focused too much on rote memorization rather than problem-solving.

In the nearly 30 years since, the difficulty level of the Suneung has varied from year to year. The eight-hour exam administered in November tests students in the areas of Korean, mathematics, English, Korean history, a second foreign language or Chinese characters and “exploration” subjects such as social studies, science or vocation.

The Suneung also tests students on a wide array of concepts. The math section, for example, delves into complex equations and requires students to solve questions without a calculator, unlike the internationally recognized International Baccalaureate and Advanced Placement tests that approve of calculator use.

The language questions are also known to be demanding. Complex reading passages with unfamiliar vocabulary and phrases appear in the Korean language and English sections -- many of which are extremely complicated yet require fast abstract reasoning and problem-solving techniques.

The language questions, in particular, have faced criticism for testing students based on how diligently they have memorized the dictionary, rather than assessing how well they comprehend the subject matter. The notoriously difficult English questions are famous for leaving even native English speakers puzzled.

The “killer questions” technically only appear in math and Korean. They are usually worth the most points and require excessive background knowledge at the level of university majors. As the name suggests, killer questions usually have a low correct answer rate, typically between 5 and 10 percent, because they aim to differentiate students’ academic levels in the top category and rank them for applying to universities.

Of the 447,669 Suneung test-takers nationwide last year, only three had perfect scores. There were test years where no student obtained a perfect score; from 2002-2007 and 2010-2011. The years 2012 and 2014 saw the most perfect scorers, at 30 and 33 test-takers, respectively.

In comparison, some 7 in 10,000, or 0.07 percent, of those who took the US-based equivalent SAT achieved a perfect score, while Korea’s comparable number for the Suneung worked out to 0.00067 percent in 2022. That means there were over 100 times more perfect scores proportionally on the SAT than the Suneung.

It is typical here for students to resort to private academies, known locally as hagwon, for years to boost their proficiency in understanding the test and to know what to expect with the help of A-list teachers.

The journey starts even before students enter high school, with some extreme cases where elementary school students enroll in specialized academies to prepare for the Suneung from a young age in order to get admitted specifically to medical school. They particularly start after-school tutoring from a young age to assure a high Suneung score and guarantee medical school admissions in a “SKY” institution -- Seoul National University, Korea University and Yonsei University -- considered the country’s top three universities.

A high school senior student surnamed Kwon told The Korea Herald that the Suneung requires a high level of cognitive ability.

“The Suneung is challenging because it tests students on how far they can think and apply theories. Killer questions, in particular, ask students to solve questions based on a given condition, so you have to show great expertise when solving them,” Kwon said.

Local education experts say the test “excessively evaluates” students’ abilities to perform well at university.

“The Suneung is a college scholastic ability test, meaning it is meant to see if a student can solve a set of given problems, which is why it is not based on what students were taught (in class). There’s a reason why it’s considered tough,” Park Nam-gi, a professor at Gwangju National University of Education, told The Korea Herald.

“There are easy questions and passages, but the test has a higher difficulty rating than the SAT. The SAT measures students’ academic achievement by testing if they can ‘pass’ the test -- it’s not about the score. But the Suneung ranks students based on a nine-tier rating system, so difficult questions are needed to differentiate them,” Park added.

Woo Youn-cheol, who heads the Jinhak Educational Assessment Research Institute, echoed Park’s view.

“Korean and math are the two hardest subjects. English is not as hard because it uses the absolute grading system, meaning all students who score above a certain threshold will receive an A,” Woo said.

The questions put students’ thinking skills to the test, frequently leaving them stumped, according to Woo. Aside from the English section, questions for other subjects are even more challenging because each question is designed to assign students a specific ranking, he added.

“Students in the first percentile don’t really find the Suneung that difficult because they are well prepared for it and have the know-how to solve questions quickly,” Woo explained.

Lee Bohm, an education critic, meanwhile, said the Suneung has generally become easier in recent years, except for those killer questions.

“The Suneung is more difficult compared to the SAT, ACT and Japan’s Common Test for University Admissions, but the average difficulty level has become easier in recent years,” Lee said.

“Education Minister Lee Ju-ho lowered the difficulty when he served as minister during the previous Lee Myung-bak administration, so more perfect scorers appeared,” the critic said. Lee Ju-ho, who was appointed to be education minister by Yoon in November last year, previously served in the position from 2010 to 2013.

“What makes the Suneung seem difficult are the killer questions, not the other questions,” Lee added.