An Ofsted report has found that achievement in ICT is "inadequate" in almost a fifth of secondary schools, although standards in primary schools are much better.

Inspectors found that secondary school pupils' performance was adversely affected by the "lack of a challenge" for more able students, and "poor coverage of key aspects of the ICT curriculum".

The report, 'ICT in Schools 2008-11', found that although ICT was "good" or "outstanding" in over two-thirds of primary schools visited, the position was less positive for secondary schools, with just over a third of the secondary schools in the survey judged "good" or "outstanding".

The report draws on evidence from the inspection of ICT in 167 primary, secondary and special schools between 2008 and 2011. The ICT curriculum and qualification routes provided by nearly half of the secondary schools surveyed "were not meeting the needs of all students, which reinforces concerns raised in a previous Ofsted report", according to the schools standards body.

Ofsted chief inspector Miriam Rosen said: "Young people need to be given the opportunity to learn ICT skills in an interesting, challenging and relevant way. Schools should provide a range of ICT courses that are suitably matched to students' needs and prepare them for higher education and for skilled work in a technological age."

In 30 of the 74 secondary schools visited, said Ofsted, nearly half of students reached the age of 16 without adequate foundation for further study or training in ICT and related subjects.

The numbers studying GCSE ICT have dramatically dropped since 2007. This year 31,800 students attempted the examination compared with 81,100 in 2007 - a reduction of 64 percent. There has also been a reduction in the number of entries at A level ICT.

In both primary and secondary schools, Ofsted said, there were weaknesses in teaching "more demanding topics such as databases and programming", highlighting the need for schools to provide subject-specific support and professional development to improve teachers' confidence and expertise.

There has been criticism in some quarters that too much time in schools is devoted to simply teaching basic desktop productivity skills, instead of the science behind ICT.

Microsoft research shows that 58 percent of UK 16-18 year-olds believe they have a greater understanding of IT than their ICT teachers. The company surveyed 1,000 16-18 year-olds in education for its research, and found that the majority of students believe they are learning more about IT outside of the classroom.