Over 20,000 Leaving Cert students are expected to fill in the change-of-mind form in the next week, as the deadline for applications approaches.

The process offers students the opportunity to review the CAO choices they made in January. After completing the Leaving Cert, which ends today, some students will be reconsidering their options.

Career experts say most students are unduly pessimistic about their exam results. Many underestimate the CAO points they will secure - often on the basis of very "tough" marking in their "mock" exams at Easter.

Unfortunately, there are also other students who have unrealistic expectations of what they might achieve.

It is widely expected that CAO points for degree courses will be similar to last year. The first round of offers from the CAO will be published on August 15th and 16th - about four days after schools receive the Leaving Cert results.

Last night, a senior third-level figure advised all students to review their choices carefully.

Prof Ciaran O'Cathain, the director of Athlone IT, said there are two principal reasons why preferences on the CAO application form should now be reviewed:

"In addition, I am aware that annually, throughout the third-level system, a small number of first-year students regret their CAO choices, because of selections made either in haste or while they were still unsure of their career plans," said Prof O'Cathain.

He said the change-of-mind option should, therefore, be considered by every student.

"While the vast majority of students will decide they are happy which their original selections, for those who decide to exercise a change of mind, third-level education is likely to be a happier and much more fulfilling experience."