Previous international work has shown that clustering pupils with similar characteristics in particular schools yields no clear academic benefit, and can be disadvantageous both socially and personally. Understanding how and why this clustering happens, and how it may be reduced, is therefore important for policy. Yet previous work has tended to…

Secondary analysis of datasets can extend previous work in the field, provide a greater quantity of material, and has the advantages of speed and lower cost. More use of secondary data could improve the low esteem of educational research. (Contains 15 references.) (SK)