Head teachers angered by the poor quality of marking in this year’s national curriculum tests are sending back thousands of test papers to be marked again. Hundreds of primary schools are expected to write to the government agency responsible for exams to protest about sloppy marking and inconsistent standards.

The most talented children at some schools were penalised because the formulaic marking did not recognise their flair. Other schools discovered that right answers had been given a zero, or that wrong answers were marked as correct. Some pupils were penalised for not dotting the letter i — others were not.

The tests, formerly known as SATs, are a source of contention in schools and many heads and teachers would like them to be abolished.

Those taken by 14-year-old pupils were scrapped last year, after the results from millions of papers went missing or were delayed. ETS, the company responsible, had its £156 million, five-year contract terminated, and an investigation found a backlog of 10,000 unanswered e-mails from worried schools.

Ministers insisted that this year’s tests for 11-year-olds would run more smoothly. Government agencies boasted last week that 99.9 per cent of pupils had their results on time.

However, two teaching unions, representing the majority of primary school teachers and heads, are planning to boycott the tests for 11-year-olds next year if Ed Balls, the Schools Secretary, refuses to get rid of them.

Yesterday one of those unions, the National Association of Head Teachers (NAHT), which represents 85 per cent of primary heads, said that it was encouraging its members to write to Ofqual, the government agency responsible for exam standards. It said heads had complained of harsh and unfair marking, spellings being marked right when wrong and vice versa, little consistency in the marking of composition, clerical errors and mistakes in adding up marks.

The marking scheme was time consuming and weighted to discourage schools from returning papers for review, the union said.

The importance of dotting every “i” was brought home to West Hill Primary in Cannock, Staffordshire, where some pupils were marked down for incorrect spelling if they failed to do so, but other children who had made the omission had dots added by the marker and were given a point.

One 11-year-old pupil was given 0 out of a possible 2 marks for correctly spelling “stunning” but without dotting the i. Another child received 3 out of 12 in spelling for failing to dot the i in the words remain, various, scorching, distinctive, carrying and magical, all of which were spelt correctly.

Shaun Miles, the head teacher, has sent back eight papers out of 58. He said: “It’s bizarre and petty. The marker had used a red pen and put dots over some letters, and given some children the mark, but not others. Those who were marked as wrong were graded Level 4 instead of Level 5.”

Ian Foster, assistant secretary of the NAHT, said: “The bureaucracy and stress surrounding these outmoded tests, compounded by clear examples of inadequate marking, can be dispiriting for pupils and parents, and potentially put school leaders’ careers on the line . . . There have been comments that maybe the quality has been usurped because of the tight marking deadline.”

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