Recently policy makers have argued that improving the standard of teaching is key to improving children’s educational attainment in those schools which have the lowest levels of performance on national tests. Datasets which contain information on both teacher characteristics and pupil outcomes are rare, however. Whether the quality of teaching is a major factor in the low levels of education in some schools has therefore not been an easy question for researchers to answer, at least directly. Researchers have been able to use routinely collected administrative data, such as the National Pupil Database, to examine the relative importance of schools in explaining differences in children’s educational achievement. The overall finding from this work has been that schools only account for around ten to fifteen percent of the observed variation in children’s achievement. In other words, if all children went to the same school we would expect the variation in children’s achievement to be lower but a significant amount of variation would still exist. The emphasis placed on improving the quality of teaching as a means of increasing educational achievement in the lowest performing schools therefore seems slightly surprising.
A further indication that the main factors causing differences in children’s educational achievement are outside of schools comes from socioeconomic differences in children’s development when they first start school. In England, children’s education is divided into stages with the Early Years Foundation Stage (EYFS) covering the period from birth to age 5 years. The EYFS profile summarises children’s attainment at the end of their reception year in primary school in terms of characteristics which play a central role in learning (e.g. creating and thinking critically). Children who achieved at least the expected level of learning in each area are assessed as having a good level of development. The figure below shows the relationship between the proportion of children who have a good level of development in each local authority in England and the proportion who are eligible for free school meals using data from the Department of Education. The regression line (in blue) shows that as the proportion of children receiving free school meals in each local authority increases there is a fall in the proportion achieving a good level of development. In the local authorities with the lowest proportion of children in receipt of free school meals around 65 percent of children achieved a good level of development while in those areas with the highest proportion of children receiving free school meals only 55 percent of children showed good development at the end of their reception year.
I am not trying to argue that teaching is unimportant in learning but only question whether differences in teaching are important in causing differences in educational attainment in the population. The idea that the quality of teaching has a key role in causing differences in educational achievement might seem persuasive because most of us would probably have had one or two school teachers who we thought were really great and one or two, perhaps, who we thought were not so good. In considering the effect of teaching on children’s achievement we need to distinguish, however, between the impact of teaching on the level of attainment of the individual child and the impact on the level of attainment in the population. The importance of high quality teaching in explaining the overall pattern of children’s achievement depends both on the degree to which high quality teaching raises educational achievement and the overall proportion of high quality teachers in the teaching workforce. Although having a high quality teacher may have a strong effect on an individual child’s learning, it seems unlikely that the number of high quality teachers are sufficient to explain overall differences in educational achievement in the population. Rather, it seems likely that the impact of teaching is likely to have the most significant impact on the learning of children who have teachers of average quality simply because of the larger number of teachers in this group. This implies that rather than focusing on initiatives, such as Teach First, which aim to increase the numbers of high quality teachers in schools, strategies which try to increase educational achievement by raising teaching quality should aim to improve the quality of teaching across the entire profession. We should acknowledge, however, that few interventions are likely to significantly change the structure of educational inequalities in England on their own. Improvements in the quality of teaching are certainly worthwhile but are unlikely to significantly reduce inequalities in educational achievement without accompanying changes in the socioeconomic situation faced by many families.