England's exams watchdog is warning people not to be surprised if A-level candidates get extreme variations in their grades.

It says analysis of this year's results suggests there is nothing odd about uneven "unit profiles" - such as getting A grades in two units and failing a third.

It says uneven or extreme unit profiles - of the kind that first sparked concerns over this year's grading - "do not imply grading or marking error".

And it says there is no evidence to back up predictions that the Curriculum 2000 changes would lead to a "re-sit culture".

Inquiry

The watchdog, the Qualifications and Curriculum Authority (QCA), has just published an analysis of the 2002 A-level results.

Confusion over grading resulted in a crisis and the appointment of an independent inquiry by the former chief inspector of England's schools, Mike Tomlinson.

The QCA says the task of awarding grades was to ensure that evidence from students' scripts and previous statistics "was combined in a manner that was as fair and thorough as possible".

"This was achieved through a two-tiered procedure in which both awarding committees and accountable officers provided professional and informed judgements."

Grades changed

The "accountable officer" at the OCR exam board, chief executive Ron McLone, repeatedly overruled his committees of examiners, and ended up having to re-grade tens of thousands of students' work following the Tomlinson inquiry.

As Mr Tomlinson has said, the unit grades for almost 10,000 students were increased.

On the issue of extreme grades, the QCA says only tiny proportions of candidates - less than 1% - had results with AAU grades.

It quotes a case study by the Welsh exam board, WJEC - which was not covered by the Tomlinson review - which took A-level biology as an example.

Range of grades

It found that such uneven unit profiles were "more the rule than the exception".

• only 7% of students had the same grade across all units (all grade A)
• only 8% achieved five grades the same with one different across their AS and A-levels, most commonly five As and a B
• only one student had the most extreme unit profile of AAAUUU.

Unit profiles did however often range across four grades, for example from a B to an E.

Typical combinations included CBAABC, BBBDAB and EECDUE.

The board looked at its own English literature results and those from the OCR exam board and found similar results.

The QCA says the findings suggest that:

• we should not be surprised by uneven unit profiles
• we should expect some candidates to have extreme unit profiles
• uneven or extreme unit profiles do not imply grading or marking error.

To account for the variations, it says different units commonly assess different aspects of the subject and some students "under- or over-perform from unit to unit".

Re-sits not common

The QCA says it had been predicted that A-level results would be substantially higher this year than last because students had the opportunity to re-sit up to three AS units.

It quotes an OCR investigation which found that this had only a small impact on A-level results.

On a sample of 10 subjects, it found that only 6% of entries were re-sits and only 36% of A-level students had re-taken any units.

Where AS units could have been sat four times, only 38 students actually did so.

Of those who did re-sit units, 17% got no higher marks and on average people gained less than one-third of a grade for their subject as a whole.

'Greater clarity'

"The Curriculum 2000 reform does not seem to have led to the national 're-sit culture' that some had predicted," the QCA says.

"However, it is too early to say whether this situation will stay the same in coming years."

But even if people do try again they will not necessarily get higher grades - because they might be taking time away from other areas of study.

The head of plans in the QCA's quality audit division, Dennis Opposs, said: "The new A-levels provide greater clarity about individual exam performance.

"Students are better able to pinpoint and address their own strengths and weaknesses because it is clearer to them how they perform across the different aspects of the subjects.

"Higher education and employers will be better able to gauge a students individual strengths in particular areas."