[2025 CSAT] "Korean, English, Math Easier Than Last Year"... Concerns Over 'Top-Tier Differentiation' (Comprehensive)

Entrance Exam Industry "Harder Than September Mock Test"
"Difficulty in Securing Differentiation May Occur"
EBS States "Appropriate Differentiation Secured"

Regarding the difficulty levels of the Korean, English, and Mathematics sections of the 2025 College Scholastic Ability Test (CSAT) held on the 14th, EBS analyzed that all three subjects were easier than last year's CSAT. The admissions industry generally evaluated the test as easier than last year's CSAT but more difficult than the September mock exam this year. However, concerns were raised that, given the largest-ever number of repeat test-takers (graduates or above) participating this year, it might be challenging to secure sufficient discrimination to differentiate top-tier scores.

At the '2025 CSAT Question Trend Analysis Briefing' held at the Government Sejong Complex on the same day, Yoon Yoon-gu, a teacher at Hanyang University Affiliated High School of Education, commented on the overall assessment of this CSAT: "The 2025 CSAT was easier across all sections compared to the 2024 CSAT. It appears that the questions were arranged to secure appropriate difficulty and discrimination, reflecting the students' preparation status confirmed through the June and September mock exams."

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He added, "The questions were designed to measure mathematical ability by assessing concepts and thinking skills that must be covered in the high school curriculum, aligning with the fundamental purpose of the CSAT. So-called 'killer questions' (extremely difficult questions) were excluded to ensure fairness."

However, Jongno Academy stated on the same day, "The test was set at a level that could cause significant problems in securing competitiveness among top-tier medical school applicants," adding, "Especially in Korean and Mathematics, there were many ties among students in the top 1st-grade bracket, and even students who scored perfect scores in Korean and Mathematics might find it difficult to secure competitiveness." They further noted, "Even if students receive high raw scores, the situation is not one to be optimistic about."

On the other hand, Etoos Edu analyzed, "Although variables remain in the inquiry section, the CSAT secured a certain level of discrimination." They added, "Both Korean and Mathematics are expected to have maximum standard scores in the high 130s, so it cannot be said that the test was simply easy. English was also slightly more difficult than the September mock exam, so the number of students achieving the top grade will not exceed 10% by a large margin."

Daesung Academy also commented, "Overall, the test was somewhat easier than last year's CSAT but, as an integrated CSAT for humanities and sciences, it was sufficiently discriminative." However, they explained, "Since Korean was easier, Mathematics is expected to have a relatively greater impact on admissions strategies."

Korean "At the level of this year's September mock exam"

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Han Byung-hoon, a teacher at Cheonan Central High School and a member of the EBS on-site teacher group analyzing the first session Korean section, explained, "The test maintained the question trend of the September mock exam this year, aiming to measure reading comprehension and thinking skills learned through school education," adding, "The overall difficulty was easier than last year's CSAT." Last year's Korean section was evaluated as a 'very difficult test,' but the September mock exam this year was widely regarded as easier.

He continued, "The amount of information in the passages was appropriate, and the passages were at a level studied through textbooks," adding, "So-called 'killer questions' were excluded."

The EBS linkage rate for the Korean section was 51.1% (23 questions). The teacher said, "Following the direction to maintain the linkage rate and method while increasing the perceived linkage, it is expected that students will feel a strong sense of connection especially in literature. In literature, modern and classical poetry were presented in full, and most of the classical novel passages matched scenes included in the EBS CSAT-linked textbooks."

Questions with high discrimination included reading questions 7 and 13, literature question 27, speech and composition question 45, and language and media question 39. The teacher explained, "Question 7 requires understanding the core arguments of 'Park Eun-sik' presented in (a) and 'intellectuals of the New Culture Movement' mentioned in (b), as well as understanding and comparing their detailed positions on the acceptance of Western science and technology, making it a discriminative question."

When asked whether the test could secure discrimination at a difficulty level similar to the September mock exam, which was widely regarded as easy, the teacher replied, "Securing discrimination is important not only for the top tier but also for distinguishing among upper, middle, and lower tiers. I analyzed that sufficient questions to differentiate the top tier were included in this exam."

He added, "Although the September mock exam and this CSAT are close in timing, the populations differ, so the results cannot be predicted to be identical. Nevertheless, since the question trends and difficulty levels of the September mock exam were followed to some extent, similar results are expected. After the September mock exam, detailed difficulty adjustments were analyzed in the answer choices considering students' preparation levels."

The admissions industry analyzed that the test was easier than last year's CSAT but similar to or more difficult than this year's September mock exam. Many noted that unfamiliar questions, rarely seen before, appeared in the literature and language and media sections.

Jongno Academy stated in their analysis, "Although it was somewhat easier than last year's very difficult CSAT, it was set at a level that can secure basic discrimination," adding, "It cannot be generally regarded as an easy Korean test." They also noted, "In the literature section, unfamiliar works not linked to EBS questions appeared in poetry and novels, which may have felt unfamiliar to students," and "Grammar questions in the language and media section were somewhat difficult."

Last year's CSAT Korean section recorded the highest standard score (perfect score) of 150 points, considered the most difficult ever. In contrast, the highest standard score in the September mock exam was 129 points, the lowest since the September mock exam of the 2022 academic year.

Meanwhile, MegaStudy Education diagnosed the test as similar to the September mock exam. They interpreted, "Following the principle of excluding killer questions, no particularly difficult questions were set, and the test consisted of questions that students who have improved their thinking and reading comprehension skills through study could solve." However, regarding the reading section, they noted, "The format of the options was unfamiliar, which may have confused students," and in the language and media section, they expected that questions 43 and 45 might have required more time to solve.

Mathematics "Difficulty varies by elective subject"

EBS analyzed that the 2025 CSAT Mathematics section was clearly easier than last year's CSAT. While the 22nd question in last year's CSAT, the first test after deciding to exclude so-called 'killer questions,' was perceived as highly difficult by students, this year's test featured questions with much easier calculations.

Shim Ju-seok, a teacher at Incheon Haneul High School and a member of the EBS on-site teacher group analyzing the second session Mathematics section, said, "Some questions requiring comprehensive thinking might feel somewhat challenging to some students, but overall, it was clearly easier than last year's CSAT."

Shim emphasized, "Questions of varying difficulty levels were evenly presented. However, 'killer questions' such as those involving content not covered in the public school curriculum, requiring excessive calculations, or causing mistakes due to unnecessary concepts were excluded."

The test was evaluated as matching the 'perceived difficulty' of the September mock exam, which was easier than last year's CSAT. Shim said, "Generally, if the September mock exam and CSAT are set at the same level, students' scores naturally improve over the two months due to diligent study. The first goal of the CSAT is to make students feel the same perceived linkage as in September. This CSAT was closer in difficulty to the September mock exam than last year's CSAT."

Last year's CSAT Mathematics section had a highest standard score of 148 points, and the September mock exam this year had 136 points.

EBS pointed out discriminative questions such as question 22 related to the inductive definition of sequences in Mathematics I, question 21 on the limit of functions in Mathematics II, question 29 on the meaning and properties of the normal distribution in Probability and Statistics, question 30 on inferring the shape of function graphs in Calculus, and question 30 on using the inner product of vectors in Geometry.

The linkage rate with EBS textbooks was 50%, with 11 questions linked in the common subjects Mathematics I and II, and 4 questions each in the elective subjects Probability and Statistics, Calculus, and Geometry. Shim noted, "The linkage in Mathematics involved applying conceptual principles and transforming questions into material situations. Notably, all highly discriminative questions in Mathematics I were linked to EBS textbooks, and some questions had very similar problem-solving algorithms."

When asked if there were questions of similar difficulty to last year's 22nd question, which students found to be a 'killer question,' Shim replied, "There is no question like last year's 22nd question." He explained, "Last year's 22nd question involved fractions in the process of finding coefficients, requiring common denominators in equations, which might have been judged as difficult. However, this year's 15th question provided all function coefficients as integers from the start, making calculations simpler."

He also added that last year's 22nd question was not a 'killer question.' Shim said, "It is different from questions with excessive calculations, complex function inference processes, or those where private education skills can shorten solving time. The 22nd question is definitely not a killer."

The admissions industry evaluated the test as easier than last year's CSAT but more difficult than this year's September mock exam. It was analyzed that the common subjects were easy, but difficulty gaps occurred among elective subjects.

Jongno Academy stated in their analysis, "The common subjects were generally easy, making the overall difficulty somewhat easier than last year," adding, "Basic discrimination is maintained, but discrimination among top-tier students, such as those applying to medical schools, might be lower than last year." However, they explained that among elective subjects, Calculus and Geometry were set at a similar or slightly more difficult level than last year. Difficult questions included common subject question 20 (exponential functions), and among electives, Calculus question 30, Geometry question 28, and Probability and Statistics question 30.

English "Between last year's CSAT and September mock exam"

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EBS analyzed that the 2025 CSAT English section was easier than last year's CSAT. The top grade (1st grade) ratio is expected to be formed between last year's CSAT and this year's September mock exam.

Kim Ye-ryeong, a teacher at Daewon Foreign Language High School and a member of EBS analyzing the third session English section, evaluated, "This year's CSAT English section secured discrimination through questions requiring precise interpretation of passages and choices," adding, "It was easier than last year's CSAT and appears to have maintained a public education-centered question setting policy."

The CSAT English section, graded on an absolute scale, has seen fluctuating difficulty since the 'killer question exclusion policy' was applied last year. The top grade ratio (90 points or above) was 4.71% in last year's CSAT. In the June mock exam, only 1.47% achieved the top grade, the lowest since the absolute grading system was implemented in the 2018 academic year. However, in the September mock exam, it rose again to 10.94%, more than double last year's CSAT.

This test's difficulty was seen as easier than last year's CSAT but more difficult than the September mock exam. Kim said, "There was a large fluctuation in the top grade ratio between the June and September mock exams," adding, "I think several questions required a bit more time management than in the September mock exam."

He also evaluated that killer questions were excluded. Kim explained, "Many questions require careful reading of the entire question based on reading comprehension and comprehensive thinking skills, and precise understanding of the meanings of choices to find the answer." Discriminative questions included numbers 33, 34, 37, and 39. The EBS linkage rate was 55.6% (25 questions).

The admissions industry generally analyzed the test as easier than last year's CSAT. Compared to this year's September mock exam, which was widely regarded as easier, evaluations were mixed. Etoos Edu stated in their analysis, "The English section was easier than last year's CSAT and this year's June mock exam but slightly more difficult than the September mock exam." The top grade ratios for last year's CSAT, this year's June mock exam, and September mock exam were 4.71%, 1.47%, and 10.94%, respectively.

However, Jongno Academy said the English section was "set at a difficulty similar to last year's CSAT," adding, "Overall, the questions were difficult to understand in terms of passage content, so it is expected that solving the questions took a long time." They further predicted, "Although English is graded on an absolute scale, the top grade ratio was set similarly to relative grading, so meeting the minimum CSAT score requirements in English might not be easy."

The admissions industry pointed out questions expected to be difficult for students, including question 21 on implied meaning types, question 33 on blank inference, question 37 on arranging the order of passages, and question 38 on sentence insertion types.