Schools which present pupils a year early for exams are boasting of "stunning" results, calling into question the Government's plans to put off exams until S4.
Under the proposed reforms, Standard grade and Intermediate exams are to be replaced by a new S4 qualification. Fiona Hyslop, the Education Secretary, wants to see pupils studying a "broad curriculum" in S1-3.
However, headteachers claim the demise of early presentation for exams in S3 will disadvantage some youngsters, particularly the less able.
Those pioneering the approach argue that making subject choices early motivates the pupils who are hardest to engage and eradicates the problem of "marking time" during the first two years of secondary.
This year for the first time, pupils at Larbert High near Falkirk were presented for national qualifications in all subjects a year early. Headteacher Neal McGowan summed up the third years' performance as "excellent" and "stunning".
For high-achievers, early presentation made little impact: 33 per cent of S3 pupils, some no more than 14 year old, got five or more awards at SCQF level 5 (equivalent to a Standard Grade Credit award); S4 did better with 34 per cent.
However, the "spectacular results" came for other pupils. In S3, 83 per cent of pupils achieved over five awards at SCQF level four or better (Standard grade General or equivalent), compared to 76 per cent in S4.
When Foundation awards are taken into account, 97 per cent of S3s in Larbert High attained more than five awards over the three Standard grade levels, compared with 90 per cent who sat their exams in S4.
Mr McGowan said: "Two things have happened: the top performing children in S3 have held their ground with those in S4, and the performance of the middle and lower ability pupils in S3 has outstripped current and previous S4s."
Early presentation impacted most on the less able pupils, who can drift away from school as they get older and can be "completely disengaged" by S4, he added.
He suggested that a by-product of early presentation and early motivation would be better qualifications. "I'm confident that when these youngsters exit S5, they will do so with really strong qualifications," he said. "If we don't find a way to keep them focussed and engaged, we will not only return to marking time in S1 and S2 but in S3 as well."
Dalziel High in Motherwell is reaping the rewards of presenting pupils early in English and maths. Next year, all S3 pupils will have the option of sitting their Standard grades a year early in all subjects.
Last year, the number of the school's S5 pupils passing Higher English leapt from 37 to 61 when the first cohort to take Standard grades in third year sat their Highers. This year, the improvements have continued, with 70 pupils passing the exam.
The numbers achieving a pass in Higher maths increased from 30 to 44 between 2006-07; this year, they remained stable at 42 passes.
Headteacher Brian Miller said: "For the second year running we have improved results in English dramatically, and our maths results are near identical. We're delighted."
Commenting on the proposal for a broad, common course from S1-3 and delaying exams until S4, Mr Miller said it was "nut case stuff" if there was no personalisation or choice. He added: "If a common course is no good in S1 and S2 because pupils are treading water, why would it work over three years?"
Other heads would also express their "strong views" about the loss of early presentation during the current consultation on the Government's qualifications proposals, according to Brian Cooklin, president of School Leaders Scotland (formerly the Headteachers' Association of Scotland).
"There is a concern that the loss of early presentation would disadvantage some children and prevent the gains that have been made from being carried forward for other pupils in the future," he said.
- Mr Cooklin said problems with teacher predictions varying widely from pupil results in Higher English appear to have been resolved this year.
Last year, headteachers reported that not only did they have pupils who were under-performing compared to departmental expectations, but they had others who were getting much better passes than predicted.
According to Mr Cooklin pupils predicted for an "A" were getting a "C", and vice versa. "There was a very narrow gap between an "A" and a "C" - just 10 marks - and that meant people were getting widely different results," he said.
An investigation by the Scottish Qualification Authority, following pressure from secondary heads, led to changes. "The fact that they changed the marking scheme on the critical essay paper appears to have made a difference," he said.
The pass rate for Higher English went up from 64.9 per cent to 68.3 per cent, a bigger increase than that for Highers overall but a lower pass rate than the average for the exam, which was 73.4 per cent compared with 71.7 per cent in 2007.