Ministers should stop relentlessly pressuring schools to push up results year after year, one of the foremost experts on school improvement said this week.
Few schools can keep improving for more than three years and the performance of most wobbles up and down, said Barbara MacGilchrist, deputy director of London University's Institute of Education. Even the most successful schools tended to "hit a wall" after three years of continuous improvement in results, she said.
"The Government's current definition of school improvement is simplistic and has passed its sell-by date," she argued in a professorial lecture on Wednesday.
"An over-emphasis on performance is having a negative impact on the curriculum and the quality of learning for primary children," she said.
"The long-term consequences of this are serious."
In the week the Prime Minister launched the Government's strategy for schools in London (see facing page), which threatens to close down underperformers, Professor MacGilchrist called for an end to "naming and shaming" of schools.
While pressure on schools needed to continue, perhaps in the form of "consolidation targets" - meaning schools agree to sustain performance at their current level - it should be balanced by more support, especially for schools in challenging circumstances.
Ministers should also shift emphasis from performance to learning. Instead of judging improvement only by exam results, they should look at other factors such as improvements in teaching.
At key stage 2, where the national proportion of pupils scoring level 4 or above has been stuck at 75 per cent since 2000, she found great local volatility. In both 2000 and 2001, for instance, the performance of about half of primaries went up and of the other half went down - schools improving in 2000 often declined in 2001 and vice versa.
Even schools singled out for praise by inspectors saw their results slip.
Professor MacGilchrist took nine primaries defined by inspectors as "excellent" in 1996 and one that had emerged from special measures. She tracked their progress from 199899, when the literacy strategy was introduced.
Only two "excellent" schools managed to improve their results for as much as three years, after which they declined. The results of one then declined for three years - which could have put the school in special measures if the inspectors had visited at the end of that time.