Circular 10/65 and withholding funding from any school that sought to retain selection. This circular was vehemently opposed by the grammar school lobby. Some counties procrastinated and retained the Tripartite System in all but a few experimental areas. Those authorities have locally administered selection tests. The Circular also requested consultation between LEAs and the partially state-funded direct grant grammar schools on their participation in a comprehensive system, but little movement occurred. The 1970 report of the Public Schools Commission chaired by David Donnison recommended that the schools choose between becoming voluntary aided comprehensives and full independence. This was finally put into effect by the Direct Grant Grammar Schools (Cessation of Grant) Regulations 1975. Some schools (almost all Catholic) became fully state-funded, while the majority became independent fee-paying schools. In 1973 the introduction of the Education (Work Experience) Act allowed LEAs to organise work experience for the additional final year school students. In some counties around the country, these changes also led to the introduction of Middle schools in 1968, where students were kept at primary or junior school for an additional year, meaning that the number of students in secondary schools within these areas remained virtually constant through the change. , there are now fewer than 400 middle schools across England, situated in just 22 Local Education Authorities. Raising of school leaving age (ROSLA) In 1964, preparations had begun to raise the school leaving age to 16 to be enforced from 1 September 1973 onwards. This increased the legal leaving age from 15 to 16 and for one year, 1973, there were no 15-year-old school leavers as the students, by law, had to complete an additional year of education. Many secondary schools were unable to accommodate the new 5th year students. The solution to the problem was to construct new buildings (often referred to as "ROSLA Buildings" or "ROSLA Blocks") for the schools that needed to extend their capacity. This provided the space to cope with the new cohort of ROSLA students. The ROSLA Buildings were delivered to schools in self assembly packs and were not intended to stand long-term, though some have proven to have stood much longer than was initially planned and were still in use in the 2010s. Primary schools The 1967 Plowden Report advocated a more child-centred approach to primary education, and also supported the introduction of middle schools. While many of the report's recommendations were