September Mock Exam Difficulty Analysis: Korean and Math Rated Harder Than June, English Easier
2026-09-02 marked the September mock evaluation for the 2027 academic year College Scholastic Ability Test (CSAT). As of 5 p.m., analyses suggest that Korean and mathematics were more difficult than this year's June mock evaluation, while English was easier than recent exams. However, the grade cutoffs currently available are not final results. Objections to questions and answers will be accepted until 6 p.m. on September 5, and the final answers will be released at 5 p.m. on September 15.
The most important thing to examine immediately after this exam is not a single predicted grade cutoff. Instead, students should identify which subjects showed score changes compared with the June mock evaluation and distinguish changes in their actual ability from changes in exam difficulty.
September 2026 Mock Exam: What We Know About Its Difficulty So Far
The September mock evaluation for the 2027 academic year CSAT began at 8:40 a.m. on September 2. The Korea Institute for Curriculum and Evaluation (KICE) stated that the questions were designed to align with the content and level of the high school curriculum. The institute also said it sought to maintain the exam's ability to distinguish between students within the public education curriculum while excluding questions that would favor students who had repeatedly practiced specialized problem-solving techniques through private education.
A review of analyses released through the afternoon by EBS teachers working in schools and private admissions institutions indicates that students experienced different levels of difficulty across subjects.
Korean was assessed as somewhat more difficult than this year's June mock evaluation and roughly comparable to last year's September mock evaluation and CSAT. Analysts noted that the difference was particularly noticeable in questions requiring students to evaluate answer choices accurately using evidence from the information provided, rather than simply understanding the content of a passage.
Most analyses also found mathematics more difficult than this year's June mock evaluation. EBS assessed its difficulty as close to last year's September mock evaluation and CSAT, while admissions institutions highlighted an increase in the perceived difficulty of the common-subject section. In contrast, the elective subjects, including Probability and Statistics, Calculus, and Geometry, were generally considered relatively manageable.
English followed a different pattern. EBS and several admissions institutions assessed it as easier than last year's CSAT and this year's June mock evaluation. This does not mean every question was easy. Certain question types requiring precise reading comprehension, such as paragraph sequencing and sentence insertion, were still considered effective at distinguishing students by ability.
Therefore, students whose preliminary scores are lower than in June should not immediately conclude that their academic ability has declined. For Korean and mathematics in particular, changes in the difficulty of the exams themselves must also be considered.
Predicted Grade Cutoffs Are Not Final Grade Cutoffs
One of the most frequently searched pieces of information immediately after the exam is the September mock exam grade cutoff. However, figures available on the afternoon of September 2 cannot be regarded as final grade cutoffs.
Admissions institutions calculate their real-time predicted grade cutoffs using samples submitted through their own scoring services and estimates of standardized scores. Because the composition and size of the participating student samples, as well as the calculation methods, differ between institutions, the figures may vary even at the same time.
Korean and mathematics are particularly complicated because they include elective subjects. Even when students receive identical raw scores, their standardized scores are calculated through an adjustment process involving the common and elective sections. It is therefore difficult to determine a student's grade simply from a particular raw score.
On exam day, the following sequence is more practical.
1. First, calculate your preliminary score using the official answer key.
2. Do not treat the predicted grade cutoff from a single institution as a confirmed result.
3. Compare changes in your raw scores by subject with the June mock evaluation.
4. Classify incorrect answers according to insufficient conceptual understanding, misinterpretation of conditions, lack of time, or calculation errors.
5. Compare the results again once the final answers and official scores are released.
More important than the grade cutoff is determining whether the reasons behind a particular score are the same as or different from those in the previous exam.
Korean: Examine How You Made Mistakes Before Focusing on Your Score
Because analyses indicate that Korean was somewhat more difficult than this year's June mock evaluation, it is too early to make major changes to your study strategy based solely on a decline in your raw score.
According to EBS, questions in the reading section that required students to understand multiple pieces of information together or compare evidence before reaching a conclusion were particularly effective at distinguishing levels of ability. In literature, simply knowing the works was not enough; accurately connecting the given conditions with the answer choices was also important.
After calculating a preliminary score, it is better to identify why each answer was incorrect rather than merely recording the question numbers.
If you could not understand the passage itself, the problem lies in your reading comprehension process. If you understood the passage but chose incorrectly between two answer options, you need to practice identifying the evidence supporting your judgment. If you ran out of time and could not properly complete the final passage, your first priority should be improving time allocation rather than increasing the amount you study.
It is also worth examining the connection with EBS materials. According to KICE, the EBS linkage rate for Korean, measured by the number of questions in the subject, was 53.3%. Rather than simply checking whether you recognized topics connected to EBS materials, it is more directly useful for CSAT preparation to determine whether encountering familiar material actually reduced your problem-solving time.
Mathematics: Examine the Difference in the Common-Subject Section Separately
Looking only at your overall mathematics score can make it difficult to identify what needs improvement. Because analyses indicate that the common-subject section was perceived as more difficult than in this year's June mock evaluation, students should examine their performance in Mathematics I and Mathematics II separately from their elective subject.
EBS assessed the difficulty of this mathematics exam as similar to last year's September mock evaluation and CSAT. The EBS linkage rate, measured by the number of questions, was 50%, with 15 of the total 30 questions assessed as linked to EBS materials.
If your mathematics score declined, you can divide your incorrect answers into three categories.
If you could not determine how to approach a problem from the beginning, the main issue is connecting mathematical concepts. If your approach was correct but solving the problem took excessively long, you need to practice reducing unnecessary calculations and steps when working through familiar question types. If you completed the solution but still got the answer wrong, you should look for mistakes involving signs, overlooked conditions, or calculation steps.
Even when two incorrect answers are both worth 4 points, different causes require different study priorities during the remaining preparation period.
If English Was Easier, Focus on Consistency Rather Than Whether You Reached Grade 1
Analyses generally agree that English was easier than last year's CSAT and this year's June mock evaluation. Because English uses an absolute grading system, maintaining a target grade even on a difficult exam is more important for high-performing students than achieving a higher score on a single test.
If your score increased substantially on this exam, you should compare the types of questions you answered incorrectly in June and September before concluding that your English ability has improved dramatically.
You need to distinguish whether your accuracy genuinely improved on time-consuming question types, such as fill-in-the-blank, sequencing, and sentence insertion, or whether your score rose because the overall exam was easier.
Conversely, if you failed to reach your target score despite assessments that English was easier, your priority should be identifying the causes of your mistakes rather than adding more new practice books. Repeated mistakes on an easier exam can also change your grade on the actual CSAT.
Check the Schedule Following the September Mock Exam
Not all results are finalized through preliminary scoring on exam day. KICE will accept objections concerning questions and answers from September 2 until 6 p.m. on September 5.
The objection review period will run from September 7 through 15, and the final answers are scheduled to be released at 5 p.m. on September 15.
Individual score reports are scheduled to be issued on September 29. Students will then be able to check their official standardized scores, percentile ranks, and grades, making it possible to compare the predicted grade cutoffs available on exam day with the actual results.
KICE has stated that its EBS linkage policy for the 2027 academic year CSAT targets approximately 50% of questions in each subject or section. For this September mock evaluation, subject-specific linkage rates were also released, including 53.3% for Korean, 50.0% for mathematics, and 55.6% for English.
The September mock exam should not be viewed as a direct copy of the actual CSAT questions. Nevertheless, it is particularly meaningful as the final KICE-administered mock evaluation, offering students an opportunity to examine how concepts and source materials are used in exam questions.
The most important task now is not repeatedly refreshing predicted grade cutoffs. Instead, it is identifying questions you answered incorrectly for the same reasons in both the June and September mock evaluations. Weaknesses that recur across both exams should be the first areas addressed during the remaining CSAT preparation period.
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