STUDENTS at Bolton School were horrified to discover they had answered questions on the wrong set text for their A-level English literature exam.

But the exam board has reassured the school that no students will be penalised over the mix-up.

Students in the Girls Division spent months studying Joseph Conrad's Heart of Darkness.

The syllabus, set by the Midlands-based exam board OCR, had stated that students should study one pre-1900 text and one post-1900 text.

Bolton School headmistress Jane Panton explained that Heart of Darkness was written in 1898, so teachers used it as their pre-1900 text. But during the exam two weeks ago, one of the girls realised the exam board had categorised the novella as a post-1900 work because it had not been published until 1902.

Staff immediately contacted the exam board, fearing the girls could lose 15 per cent of their marks.

Miss Panton said: "The exam board said we werent the first school to contact them on this one."

Despite the mix-up, the board agreed to mark the Conrad work as though it fell into their pre-1900 category.

Letters have been sent to parents reassuring them that the girls will not be penalised.

A spokeswoman for OCR claimed that on the syllabus listing the books which could be studied, all the pre-1900 works had an asterisk next to them. Heart of Darkness did not, indicating that examiners were treating it as post-1900.

The spokeswoman added: "We recognise that Heart of Darkness was published in serialised form in 1898.

"However, it was first published as a complete book in 1902.

"If the specification is read hastily, it is an understandable mistake to make.

"OCR would like to reassure everybody that no candidates will be disadvantaged."