GCSEs 2013: Top grades fall for second year in a row
23 August 2013 Last updated at 00:06 BST
There has been a drop in the proportion of GCSE exam entries awarded top grades, for the second year in a row.
More than 600,000 teenagers in England, Wales and Northern Ireland are receiving results, with head teachers saying changes have caused "a lot of turbulence" in grades.
Gillian Hargreaves reports.