School Segregation Data Linked to Next Steps, Sweeps 1 to 8, 2003-2006

The authors of the dataset used the publicly available school level data from the NPD and identified relevant data on the composition of the disadvantaged groups in the school population of full-time equivalent student. In particular, they used six common indicators of disadvantage in schooling that have been identified as potential factors of school stratification by social group: 1) the number of pupils taking free school meals (FSMt), 2) the number known to be eligible for free school meals (FSMe), 3) the number known to have a statement of special educational needs (SENs), 4) the number known to have special needs without a statement (SENn), 5) the number known to have English as a second or additional language (ESL/EAL), and 6) the number classified as white British ethnic origin (NW) The relevant figures for each indicator per school in each year were converted into what has been termed the Gorard Segregation Index (GS) and the Dissimilarity Index (D) at a national level in order to probe into the main characteristics of school segregation: The Gorard Segregation Index (GS) is an index of segregation between schools that refers to “the proportion of potentially disadvantaged students in a school system who would have to exchange schools with another (non-disadvantaged) student for there to be no segregation by disadvantage between schools in that school system (or the area under consideration)” It has the same basis as the disparity ratio used in studies of health. The Dissimilarity Index (D): the residual for D is the absolute value of the result of subtracting the population proportion of non-FSM pupils in each school from the population proportion of FSM pupils in each school; D itself is the sum of these residuals for all schools, then divided by two.