A total of 141 Scottish secondaries took part in a survey of upper secondary carried out by the Organisation for Economic Co-operation and Development in 14 European and two non-European countries in 2001-02.
But, the Scottish Executive said in its report on the Scottish findings released this week, "the definition of upper secondary education that was used in Scotland was not consistent with that used by other countries that took part and, to ensure that misleading comparisons were not made, Scotland withdrew its data from the international report".
The OECD definition of upper secondary is that it begins after nine years of compulsory schooling and runs to pre-degree level. But the starting age varies across countries, from 14 to 16 years, as does the duration (sometimes even within the same country).
Comparisons are further undermined, the report states, because some countries provide academic and vocational upper secondary education in the same institution while others do not.
If the OECD definition had been used, the Scottish data would have had to include pupils from S3 to S6 as well as some FE students, making Standard grade an upper secondary qualification. The Scottish data was therefore restricted to S5 and S6 pupils and to students in FE on courses below degree level.
The result is that the Executive has been forced to admit that little of the picture which emerges "will be new to the Scottish reader for whom the main benefit would have been to compare Scotland with other OECD countries".
The Scottish report covers a number of aspects of the final years of schooling, including unremarkable findings like the fact that 99.8 per cent of state school funding comes from the Government.