National high school exam scores do not accurately reflect students' abilities

Professor Nguyen Van Tuan, University of New South Wales (Australia), shares his perspective on the national high school exam and its effectiveness in assessing students' abilities.

Last week, the shortcomings of the national high school exam were mentioned a lot. The score distribution tables in some provinces are a sign that there are many irregularities, and indeed through verification, we know that there is cheating in the exam. But these analysis results also reflect that the exam scores do not accurately and reliably reflect the level of candidates. This also means that merging the two exams into one is probably a hasty decision.

There are so many issues to be raised in this year's national high school exam, and many experts in the industry have mentioned them.First of all, there was the surprise that the Math exam was too difficult. Some math professors said that it was impossible to answer all 50 questions in the 90 minutes allowed. With just a simple calculation, it can be estimated that out of nearly a million candidates, only 5 people would have a score of 0 (if all were randomly selected). But in reality, there were 951 candidates (some places reported 830 candidates) who had a score of 0. If this is a real score of 0 (not due to other factors), it is indeed a very rare phenomenon, and a signal that there is a problem with the exam.

In general, the distribution of math scores in some provinces seems unusual. The distribution of math scores in Ha Giang, Son La, and Hoa Binh all deviate significantly from the national distribution. In the whole country, only 0.056% of candidates have a math score equal to or higher than 9, but in Ha Giang this proportion is nearly 1.8% (ie 32 times higher than the national proportion). Similarly, the proportion of candidates in Hoa Binh and Son La with a math score of 9 or higher is also higher than the national proportion, and these differences are statistically significant.

The analysis results raise the question of whether we should return to the previous way of doing things, that is, maintaining two high school graduation exams and university entrance exams?

In foreign countries, such as Australia, there is only one high school graduation exam and universities rely on the results (scores) of this exam to recruit students according to predetermined standards. This one-exam solution is considered highly effective because it saves the state budget and students' efforts can be spent on university and postgraduate studies. However, in Vietnam, this year's results show that the one-exam solution is not the best solution.

More than ten years ago, in the book “Thinking about traditional and modern education” (Tre Publishing House, 2003), Dr. Duong Thieu Tong analyzed that the average score of students taking the university entrance exam was still very low, only about 8.3 to 8.4 (out of a maximum of 30 points). About 87% of candidates had an exam score below 15. This year, the median score for group A was 15.5, and the 75% percentile was 18. That is, the national high school exam score was much higher than the university entrance exam score.

But even more importantly, high school graduation and university entrance exam scores do not correlate with students’ learning ability. For Mathematics, an analysis of 1,280 students showed that the correlation coefficient between 12th grade graduation scores and university entrance exam scores was 0.17; between 12th grade graduation scores and scores at the end of the university program was 0.09; and between university entrance exam scores and scores at the end of the university program was 0.19.

In other words, high school graduation exam scores are not a predictor of college entrance exam scores and have no significant relationship with grades in the final year of college. More specifically, students with low scores in high school graduation still have high scores when taking the college entrance exam and when graduating from college; conversely, most students with high scores in high school graduation exams do not have high scores in college.

There are many ways to interpret the above statistics. Among those interpretations, it is possible that (a) high school graduation exam scores do not distinguish students' abilities when they enter university; or (b) high school graduation exam questions do not match the academic needs of university; or (c) it is the fate of students, like "studying talent, taking the exam is fate". I do not believe in fate, but based on the facts presented above, I tend to favor (a) and (b), that is, the current examination system does not honestly reflect the level and potential of students. More specifically, current high school graduation exam scores (and university entrance exam scores) cannot be used as a standard for selecting students.

I find the content of the high school graduation exam or university entrance exam in Vietnam more challenging than testing the students' level. Over the past few decades, the exam questions for each subject have not changed significantly: the questions still focus on the 12th grade program. Sometimes the questions are quite "tricky", lacking practicality, even going beyond the curriculum. For example, the content of the Math exam does not reflect the entire high school program. Because the exam only focuses on grades 11 or 12, it creates opportunities for the habit of cramming, and because cramming does not reflect the students' actual learning ability.

As a side note, in Australia, the high school graduation exam (available on the NSW Department of Education website) usually consists of around 40 questions ranging from easy to difficult. "Easy" and "difficult" here are understood in the sense of testing the entire knowledge of students from Grade 6 to Grade 12. For example, the math exam for students studying Grade I (meaning average) math includes questions at the Grade 9 level, but gradually leads students to "higher" topics in Grades 11 and 12 such as derivative and integral applications. With such an exam, the Australian high school graduation exam reflects the student's level quite accurately, because a student with a good score must have a good overall score in the subject, not just a few random and challenging questions.

It is well known that students differ in their aptitudes across subjects. Some students are good at math but bad at biology; some are good at chemistry but not good at math. Even within a subject, such as math, some students are good at theory but bad at application, some are good at application but bad at theoretical topics, and some are good at both theory and application. And students’ abilities, whether theoretical or applied, need to be recognized through testing. Therefore, an ideal test should reflect these realities.

Therefore, I think it is necessary to consider preparing exam questions with content that tests knowledge of the entire high school curriculum, rather than focusing only on the grade 12 curriculum. It is hard to imagine that the entire high school curriculum can be summarized in a few questions! For example, in Mathematics, in addition to questions testing basic knowledge of algebra and equations/inequalities (grade 9 or 10 level), there should be questions on the theory and application of trigonometry, derivatives, integrals, and probability. The proposed method of preparing exam questions can more accurately reflect students' potential and abilities.

From the above reality, the issue of educational quality should probably start with textbooks, which are now said to be “unique”. Ideally, secondary school curriculum should respond to the differences in students’ abilities. This way of preparing the curriculum not only creates opportunities for students to realize their appropriate potential but also prepares students for a university course that they find suitable for their talents.

In short, the analysis of this year’s high school graduation exam score distribution shows that there are thousands of cases of unusually high scores, and we know a little about the causes of that abnormality. But the analysis also implies that national high school exam scores do not accurately reflect students’ abilities, and previous evidence suggests that they have no correlation with university admissions. Perhaps the decision to merge the two exams into one is a hasty one that could have long-term effects on education.