It was a classic "lies, damned lies and statistics" moment. On the eve of last month's national pay strike, a government minister claimed the "average" teacher earned pound;34,000.
There were angry howls from classroom staff who said the figure was too high. "No teacher in my school is on the average salary quoted. Where do they get their figures from?" said one teacher on The TES online staffroom. The BBC and other media also received complaints for repeating the figure.
The Department for Children, Schools and Families later clarified that the mean (the arithmetic average) wage figure quoted by Jim Knight, the schools minister, was for all teachers in England and Wales, including advanced skills teachers and, crucially, senior management and headteachers.
A figure of pound;32,200 was then offered for the average "classroom teacher", which included all posts except head and took account of all extra payments and allowances.
Even this figure was met with disbelief by staff who earned less and felt it was disproportionately affected by a minority on high wages. So what is the true picture?
Figures from the independent School Teachers' Review Body (STRB) suggest that the mean salary for full-time teachers last year was pound;31,435, but many received more because the median average (the middle figure) was pound;32,253.
Pessimists could dismiss those figures by pointing out that the body bases its figures on survey responses from about 1,000 of England's 22,000 schools.
But pay grades are available for all working members of the Teachers' Pension Scheme, which represents all but a handful of teachers in maintained schools. This database indicates that more than half of all full-time qualified teachers are on the first rung of the upper pay scale or above, so they earn more than pound;31,878.
Indeed, 20 per cent are at the top of the upper pay scale: pound;34,281. This represents the mode average (the most common) salary. Ten per cent have earnings that are off the upper scale because they involve extra allowances; and 15 per cent are on the leadership pay scale.
Teachers may still be glancing around the staffroom trying in vain to spot any colleague, other than the head, who earns more than the official average. But that may be because they work in primary schools.
It is clear from the figures that nursery and primary school teachers are less likely to be at the top of the pay scale, less likely to collect teaching and learning responsibility payments, or be among England's 4,280 advanced skills teachers.
While a quarter of secondary teachers are at the top of the upper pay ladder, only 15 per cent of nursery and primary teachers are on the same rung. STRB figures indicate that the proportion of teachers receiving responsibility payments is twice as large in secondaries than in primaries, and that the payments are much higher in secondaries, presumably because of school size.
The figures do not take into account the 98,470 part-time teachers or the 11,000 unqualified overseas teachers and instructors.
It is also important to bear in mind that there is a growing number of teachers working in academies who earn slightly more in exchange for working extra days.
Another key factor is London weighting. Much has been made of the extras offered to lure teachers into the capital's schools. While teachers elsewhere can expect a basic salary of pound;34,281 if they reach the top of the upper pay scale, those in inner-London earn pound;41,004.
However, the relative inexperience of many teachers in London means more are lower down the scale, which brings average wages in the capital down. Only 18 per cent of London secondary teachers are at the top of the pay scale, compared with 35 per cent elsewhere.
The median annual pay for a primary school teacher in inner London is only pound;1,722 more than in the rest of England and Wales, but the median pay in the wider London fringe zone of counties bordering the capital is actually slightly lower than in the rest of the country. Given the cost of a one-bedroom flat anywhere south of Corby, the extra London payments are unlikely to be enough.
For those experienced teachers wanting to make good money without moving into leadership, becoming an advanced skills teacher is often presented as an option. However, such teachers are an expensive luxury for a school. The top standard wage of pound;53,000 is earned by only 2 per cent of them. In primaries, a fifth of advanced skills teachers are paid pound;34,938, the lowest salary possible.
Barry Fawcett, head of pay at the National Union of Teachers, said he could not really argue with the Government's claim of a pound;34,000 average wage, but questioned whether that should really be regarded as a lot of money. Considering some teachers had to graft for nine years in the classroom to achieve it, perhaps it is nothing to get excited about, he said.
"The starting salary (pound;20,133) does not compare well with other graduates, and the salary progression is much slower. That's why even the crude average of pound;34,000 is nothing to shout about," he said. "In other careers, you can make much bigger hops forward.
"Of course, some will get teaching and learning responsibility payments or leadership positions and up their pay, and others will have increased chances of promotion by teaching science or maths, but these opportunities aren't there for anyone."
Professor John Howson, an education recruitment expert, said that despite many teachers earning at the top of the scale, it was the most frustrating position to be in.
"They are the most reliant on the cost of living increase. These teachers have stayed in, got to the top of the scale, and all they want is the Government to ensure their pay doesn't get worse," he said.
"There are probably a lot of people in primary schools who have no mechanism for increasing their salary other than leaving."
TEACHERS' PAY SCALES
Leadership - pound;34,938 to pound;98,991
Number on pay scale - 60,100
Outside pay scale - pound;34,938 to pound;53,115
Number on pay scale - 43,200
Advanced skills teacher pay scale - but other staff are on similar amounts
Upper pay scale 3 - pound;34,281
Number on pay scale - 79,300
Upper pay scale 2 - pound;33,060
Number on pay scale - 33,300
Upper pay scale 1 - pound;31,876
Number on pay scale - 27,300
Main pay scale 6 - pound;29,427
Number on pay scale - 41,200
Main pay scale 4-5 - pound;25,278 to pound;27,270
Number on pay scale - 32,500
Main pay scale 1-3 - pound;20,133 to pound;23,472
Number on pay scale - 58,200
Source: Figures for England and Wales from the Department for Children Schools and Families, the Welsh Assembly, the School Teachers' Review Body and 'The TES'.