“Just spending money isn’t going to get the outcomes that we want,” Professor Kathy Sylva of the London University Institute of Education told the conference. She presented new evidence that pupils educated with the mixed diet approach of the American HighScope under-fives programme, with its plan-do-review cycle, did particularly well when they reach primary school.

Professor Sylva and Maria Emilia Nabuco studied 219 Portuguese primary school children. Half came straight from home, but half had been to either a HighScope nursery (characterised by offering the pupils a balance of free and guided choice), a less-structured “progressive” nursery (in which children spent the vast majority of their time in free choice)or a stricter “formal skills” nursery.

The HighScope children scored better in reading and writing than pupils who had previously attended either a “progressive” or a “formal skills” nursery.

The HighScope pupils also scored well socially, showing lower levels of anxiety at primary school and higher levels of social acceptance than their peers in the “formal skills” group. Onlyin maths did the HighScope experience show no benefit.

The HighScope method, which employs a variety of formal and creative approaches, first came to prominence in the US when a study showed a sample of inner-city pupils from Detroit doing substantially better in later schooling and adult life. It has been described as a “plan-do-review” method, giving children control over their learning.

According to Professor Sylva, “the superiority in reading and writing tests shown by HighScope children was probably related to their greater involvement in literacy and cultural activities: pretending, informal conversation, stories, rhymes and songs”.

She said that a structured curriculum and properly qualified staff were also important ingredients in successful pre-school education.