There may be unintended consequences to changing the Primary School Leaving Examination (PSLE) grading system from a T-score one to one that uses grades ("PSLE grading system set to change amid broad reforms"; last Saturday).

A grade-band system is even more unfair than a T-score one because one mark could mean the difference between an A and a B grade, while pupils whose scores are 20 marks apart could end up getting the same grade.

Having many pupils with the same grade band vying for the limited places in popular secondary schools would require the need for other admission criteria to be considered, perhaps affiliation, achievements in sports or music, or distance from school.

Consider the scenario of a pupil from a low-income family who, under the old system, attains a higher T-score than one from a high-income family.

But consider that under the new grading system, both pupils get the same grade.

If the criteria suggested above are indeed used in secondary school admission, the pupil from the high-income family would have the means to attend enrichment classes to learn a new sport or to play a musical instrument, perhaps even being able to afford the time and money for extra coaching sessions to excel in these areas.

His family would also have the means to create affiliation to a desired secondary school, or purchase a property closer to such a school.

We must ensure that any changes to the education system will not make it harder for students from lower-income families to level up.

Tan Peng Boon