Striking teachers marching last week for a greater pay rise
The government has been defending its claim that the average teacher in England and Wales earns £34,000, which prompted complaints from strikers last week.
Sceptics argued that with the maximum salary for a classroom teacher being £34,281, the average could not possibly be so high.
A spokeswoman for Schools Minister Jim Knight has clarified that he was including the pay for advanced skills teachers and head teachers, deputies and assistant heads.
Even so, the average for classroom teachers is some £32,200 - which is more than many people realised.
Mr Knight told BBC News on the eve of the strike: "I think parents are bewildered because they hear that the average teacher earns about £34,000."
In a briefing to journalists sent out by his department in advance of the strike, he was quoted as saying the same thing.
Neither on air nor in the briefing was it clear that he was including in this calculation head teachers, deputies and assistants, and advanced skills teachers - who are all paid according to different salary scales.
On Monday, his department was able to point only to a figure for the average teacher's salary in March 2006, when it stood at £31,434.
A spokeswoman pointed out that it would now be higher. Teachers had a 2.5% pay rise in September, which if reflected in the average would take it to about £32,200 at present.
For teachers there are two scales. They start on a main scale on a salary of £20,133. This rises for each of the next five years to £29,427.
Any annual pay rises in percentage terms are in addition to those automatic salary increments.
Once on the top of the main scale teachers can apply to cross a "threshold" onto an upper pay scale,
This was introduced in 2000 as part of a drive by the new Labour government to reward good teachers who chose to stay in the classroom rather than move into school leadership.
The original plan was scaled back. What remains is a three-tier upper scale, on the top of which a teacher can earn £34,281.
A number of factors boost the average. One is that, because of its size, many teachers work in London, and they get paid more as a result.
Costs associated with living there mean three salary uplifts have been devised for inner London, outer London and a "fringe" area which extends well outside the capital.
A teacher on the top of the main scale in inner London earns £33,936 and on the upper scale, £41,004.
Classroom teachers who take on significant extra responsibilities, for example as subject co-ordinators, may be awarded a Teaching and Learning Responsibility (TLR) payment.
These range £2,364 to £11,557 a year.
Another factor is that teaching is an ageing profession.
Many of those on rallies during last Thursday's strike by members of the National Union of Teachers were young teachers struggling to pay off student debts. But they are unrepresentative.
A significant number of teachers do leave after only a few years - fed up, the unions say, with the workload and bureaucracy and with the misbehaviour of some pupils.
But most have been in post long enough to be on the higher salaries. Indeed a looming potential problem is a bulge in the numbers due to retire.