Korean and English Require "Background Knowledge"... Math Is "Tricky but Not a 'Killer'"

EtoosEdu Analyzes Killer Questions Identified by the Ministry of Education

As so-called killer questions (ultra-high difficulty questions) designed to differentiate scores in the College Scholastic Ability Test (CSAT) were released, an analysis showed that the difficulty level of the questions themselves was not significantly high in some subjects.

On the 26th, the Ministry of Education announced the ‘Measures to Reduce Private Education Expenses’ at the Government Seoul Office and disclosed 26 ultra-high difficulty questions from the June mock exam and the past three years of the CSAT. By subject, there were 7 questions in Korean language, 9 in mathematics, 6 in English, and 4 in science. Asia Economy, together with Etoos Edu, conducted a detailed analysis of the killer questions by subject.

On the 26th, Oh Seung-geol, Director of the Responsible Education Policy Office at the Ministry of Education, is presenting examples of killer questions from the College Scholastic Ability Test at the Government Seoul Office in Jongno-gu, Seoul. Photo by Dongju Yoon doso7@

Korean Language: “Questions that require background knowledge to solve”

Among the 7 designated Korean language questions, the killer questions were identified as June mock exam numbers 14 and 33, 2023 CSAT numbers 15 and 17, and 2022 CSAT numbers 8, 13, and 15. The average correct answer rate for these killer questions was about 28.6%.

Regarding the June mock exam question 33, which had the highest correct answer rate of 36.8%, the Ministry of Education pointed out that “it requires interpreting by connecting the content presented in each choice within the work based on limited appreciation information, demanding a lot of time and a high level of inference.” Etoos Edu explained, “This is a question type involving appreciation of works based on external criteria, and students seemed to choose incorrect answers because they could not clearly determine the meaning of ‘individuality’ related to poetic expressions.” They further analyzed, “Among the incorrect choices, option ③, which had a high selection rate, presented ‘individuality,’ a term rarely used to explain poetic expressions, causing students difficulty in judging correctness.”

For the 2023 CSAT question 17, which recorded only a 15.1% correct answer rate, the Ministry of Education stated that “the amount of information to be inferred is excessive, and since the relationships between content elements presented discontinuously in the passage must be identified by locating similar information, students who have mastered problem-solving techniques have an advantage.” Etoos Edu analyzed, “Although linked to EBS materials, only some concepts were utilized, so it likely did not greatly aid passage comprehension. The theory and concept understanding in the passage was very difficult, and if students do not accurately understand the correlation between two variables undergoing ‘relative growth,’ the question is hard to solve.”

Mathematics: “There were likely differences in solving time among students”

In mathematics, 9 questions were identified: June mock exam common subjects numbers 21 and 22, calculus number 30, 2023 CSAT common subject number 22, probability and statistics number 30, calculus number 30, 2022 CSAT calculus number 29, geometry number 30, and 2021 CSAT type B number 30. The average correct answer rate was only 6.5%. The question with the lowest correct answer rate was June mock exam common subject number 22 (2.9%), and the highest was 2022 CSAT calculus number 29 (14.0%).

Regarding the relatively easier 2022 CSAT calculus number 29 question, the Ministry of Education defined it as “dealing with a function more complex than the level covered in public education, which may cause psychological burden for examinees, and students who have studied beyond high school level can solve the problem using methods other than those expected by the examiners.” Etoos Edu also explained, “Although it is a type of question frequently appearing as a high-difficulty question, it may favor students who used approximation formulas learned in private education.”

For the June mock exam common subject number 22, which only 2.9% of all examinees answered correctly, the Ministry of Education criticized, “The problem-solving process is complex due to the combination of more than three mathematical concepts and requires a highly advanced approach, making it difficult to devise a solving method with only public education learning.” Etoos Edu evaluated, “This is a high-difficulty question mainly involving polynomial function inference, and even if students can accurately find the cubic function f(x), it likely took considerable time to calculate.”

On the 26th, Oh Seung-geol, Director of the Responsible Education Policy Office at the Ministry of Education, is presenting examples of killer questions during the announcement of measures to reduce private education expenses at the Government Seoul Office in Jongno-gu, Seoul. Photo by Yoon Dong-joo doso7@

English: “Ultimately a vocabulary battle... must know a lot to solve”

In the English section, the killer questions were June mock exam numbers 33 and 34, 2023 CSAT numbers 34 and 37, and 2022 CSAT numbers 21 and 38. The average correct answer rate in English was 24.7%. The 2023 CSAT question 34 had the lowest correct answer rate at 17.0%, while question 37 from the same exam had the highest at 29.1%.

The Ministry of Education pointed out that the 2023 CSAT question 34, which had a low correct answer rate, “may be difficult for students to understand the content even if they interpret the syntax, as it consists of long sentences using vocabulary and complex sentence structures that are generally more difficult than the level covered in public education.” Etoos Edu commented, “Even if students properly interpreted the text and grasped the main content, it likely took a lot of time. The vocabulary difficulty of the hint sentence was high and the sentence was long, so students without additional background knowledge probably perceived the difficulty as very high.”

Regarding the higher correct answer rate for question 37 in the same year’s CSAT, the Ministry of Education analyzed that “since unfamiliar subject matter is used, vocabulary must be understood in a legal context rather than its general meaning to comprehend the entire text.” Etoos Edu similarly noted, “Due to the unfamiliar topic of ‘lawyer fee system,’ it was difficult to find a logical sequence flow, so students’ perceived difficulty was very high.”

Etoos Edu stated, “In the Korean and English sections, background knowledge that is difficult to acquire through public education was utilized in the passages, meeting the criteria for so-called ‘killer questions.’ However, in the mathematics section, although many questions were not inherently difficult, they were presented in unfamiliar formats that confused students, so it is an overstatement to evaluate them as ‘ultra-high difficulty.’”

This content was produced with the assistance of AI translation services.