Getting a CSAT result sheet for the first time is disorienting. The familiar raw score is absent, and in its place are three kinds of number side by side. Worse, the three appear to tell different stories. Your percentile is high but the band disappoints; your score fell but the standard score rose.

There is nothing odd about this. The three values were built to measure different things in the first place.

Standard score — the number that carries the difficulty of the paper

The standard score expresses how far your raw score sits from the mean of that paper. It is converted using the mean and the standard deviation.

The property that follows matters. If a paper is hard the mean falls, and the top standard score rises even for the same full marks. Conversely, an easy paper yields a low standard score even with full marks.

That is why every year there are articles about "this year's top standard score in Korean". That number is also an indicator of how hard the subject was.

Percentile — the number that tells you your position

The percentile is simple: what percentage of candidates scored below you. A percentile of 92 means roughly 92 per cent of candidates are below you.

Because it shows position intuitively, it is convenient for gauging your own performance. It has a limitation, though. Towards the top, a single question's difference barely shows up in the percentile — especially in subjects where many candidates score full marks.

Band — the coarsest cut of all

The band divides candidates into nine ranges. Band 1 is the top 4 per cent and band 2 runs to the next 7 per cent.

Of the three, the band loses the most information. The top and bottom of band 2 differ considerably in ability yet carry the same number. That is why bands are barely used in regular admission and appear mainly in minimum CSAT requirements for early admission.

Why the same percentile can give different bands

A frequent question. The reason is that bands are cut by standard score, not by percentile.

Percentiles are displayed rounded, so two candidates shown as 96 may have different standard scores. Depending on which side of the band boundary that standard score falls, the same displayed percentile produces different bands. It is brutal for anyone sitting on the boundary, but that is the structure.

So what should you look at?

• For regular admission, the standard score — most universities use standard scores for Korean and mathematics. For the inquiry subjects they often use their own converted scores.
• For early admission minimums, the band — only whether the threshold is met matters, so the band boundary is everything.
• For checking your own position, the percentile — the easiest value to read when planning your study.

How each university combines these values is another matter. Why the same results give different outcomes at different universities is covered under conversion formulas in Regular Admission.

In summary

The three numbers are not competitors but tools for different jobs. The standard score speaks to the difficulty of the paper, the percentile to your position, the band to a range. Instead of asking "which number is the real one" when you look at a result sheet, decide first what you are actually trying to judge — and the number to look at chooses itself.