Despite improvements in academic standards, truancy continues to be a problem in almost half Wales's secondary schools.

The annual report of the chief inspector of schools also expresses concern that standards in information technology are unsatisfactory in 60% of secondary schools.

Chief Inspector Susan Lewis said there was still too much disparity in school performance - not just between schools, but also in the achievements of different classes in the same school.

"If schools don't follow up swiftly enough young people can get into habits and if parents don't support the school strongly enough the school is at a loss to know what to do," she said.

"We see some good practice where schools reward good attendance and contact parents when pupils are absent on the first day.

"Increasingly schools are setting targets for improving attendence but there are still a few that don't monitor attendence patterns well enough to allow this."

The report has been welcomed by Welsh Education Secretary Rosemary Butler who said she was delighted at what schools were doing to maintain standards and improve achievement - especially in literacy and numeracy.

It is the third annual report published by the inspection body, Estyn.

Last year Susan Lewis said Welsh schools were improving but could do better.

She explained that central to raising standards was the effective use of the development planning cycle, monitoring what was done, evaulating its quality, planning for targeted improvement and taking suitable action to make sure that improvement happened.

"We need to build on good practice," she added.

This year's report will be closely examined by National Assembly members who now control the purse-strings of Welsh education.