Segregating secondary school students into classes based on their ability is not beneficial, according to new report released today.
The ESRI said that so-called "streaming" has a negative effect on students with lower abilities, and has no positive effect on higher achievers.
Author of the report, Dr Emer Smith, said that streaming can lead to real problems for pupils.
"It tends to be because they become disaffected by being labelled, they begin to label themselves, they tend to have less access to higher-level subjects," she said.
"Teacher and student expectations interact, so they end up underperforming and a significant proportion of them drop out of school before the Leaving Cert."
It has also recommended a more positive approach to teaching, where students are encouraged rather than disciplined, particularly in more disadvantaged schools.