The boycott of key stage 2 Sats tests this week left local authorities in confusion and chaos as they struggled to find out exactly which of their schools took part in the action.
Although figures from a TES survey of 83 authorities indicated that around a quarter of 16,000 eligible primaries took part, several councils were left in the dark about how many schools were doing the tests.
Most had asked schools to inform them of their intentions before Sats week began, but around two thirds did not reply. More complete figures were not expected until the end of this week, when test papers are sent back to the exam board Edexcel.
Unions have estimated that more than half of schools took part in the boycott - enough to frustrate the compilation of league tables.
But a TES survey showed participation rates varied wildly.
The action may not have had any impact in some councils, such as the high-performing Kingston upon Thames, where no schools reported ditching the Sats.
Support from local authorities seems to have varied too.
The mayor of Middlesbrough, Ray Mallon, said he "fully supported" a decision to take action by at least 33 of his area's 43 schools.
In some areas, every school boycotted the Sats, after a decision on whether to take part was made jointly between heads. Some arranged for children to sit alternative tests, to be marked and moderated by other schools.
In Hartlepool, all 31 schools decided to boycott together so that their pupils would be on a "level playing field".
John Hardy, head of St John Vianney RC School in the town, said the decision meant no parent would feel their child was missing out as they moved up to secondary school. He said the local authority had remained "quite neutral" on the issue and appreciated the professionalism of heads.
"It just reflects what sort of a place Hartlepool is," he said. "We like to work together."
In Knowsley, no schools took part in the action, although it is not clear why the boycott was not supported there.
In other areas, there was more of a mixed picture. In Lewisham, schools were divided on the issue, with 22 boycotting and 47 going ahead despite the action.
In Birmingham, the largest local authority, 153 out of around 300 schools boycotted the exams.
In Richmond, which came top of the Sats league table last year, seven out of 34 schools reported taking part in the action.
It is not known how many special schools boycotted the tests, although in an average year, a quarter of pupils with moderate learning difficulties and half of pupils with emotional and behavioural difficulties attending these schools usually sit the tests.
Meanwhile, there even looked to be some variation on the council of teaching union the NAHT.
National treasurer Jack Hatch, head of St Bede CofE Primary School in Bolton, remained tight-lipped when The TES asked him if his school was taking part in the tests.
But Steve Iredale, chair of the NAHT assessment committee, and head of Athersley South Primary in Barnsley, has spoken enthusiastically about his school's participation in the boycott.
While union activists talked up the success of the action, the National Governors' Association played it down. Emma Knights, its chief executive, said: "If more than half of schools have said 'this boycott is not a good idea'. That says something really significant."
She also questioned reports that children were "jumping up and down" celebrating not having the stress of Sats this year.