There is 鈥渘o evidence鈥 setting and streaming by ability in schools harms the outcomes of disadvantaged pupils, a Professor John Jerrim, from the UCL Institute of Education and Dr Luis Alejandro Lopez-Agudo and Professor Oscar David Marcenaro-Gutierrez analysed data from the 2015 Trends in International Mathematics and Science Study (TIMSS). The paper concluded that its findings were 鈥渓argely a story of null effects鈥. 鈥淣o evidence is found that either ability grouping or mixed ability grouping is superior in terms of developing students鈥 academic self-confidence, enjoyment or test scores. 鈥淭his holds true for young people across the socio-economic spectrum, including those from disadvantaged backgrounds.鈥 It also found there was 鈥渘o evidence that teachers feel less time pressured when ability grouping is used (either in terms of lesson preparation or capacity to cover material in class)鈥. But there 鈥渁re some tentative signs that primary teachers feel more comfortable supporting struggling students 鈥 and stretching the highest achievers 鈥 when this practice is used鈥. The paper went on to say that its finding of no negative impact on poorer pupils 鈥渋s somewhat counter to prevailing narratives鈥. 鈥淥ne potential explanation is many existing studies infer low socio-economic students will be negatively affected by ability grouping based on intermediary results, rather than directly showing this to be the case. 鈥淔or instance, several studies argue low socio-economic status children tend to be placed in lower ability sets, and that those placed in lower sets make less academic progress on average than those in higher sets. 鈥淵et the direct association between between-class ability grouping and disadvantaged students鈥 outcomes on aggregate has less frequently been displayed.鈥 ‘No clear evidence’ In a , Jerrim pointed out setting and streaming was 鈥渕ore prevalent in England鈥檚 schools than in any other country鈥. 鈥淎 lot of qualitative research has been written about the potential negative impacts of such achievement grouping. Particular concern has been shown for its potential negative impacts on young people from socio-economically disadvantaged backgrounds.鈥 John Jerrim He pointed to , which likened setting and streaming to 鈥渟ymbolic violence鈥. Jerrim said one of the 鈥渒ey challenges with studying the impact of achievement grouping in England 鈥 compared to the alternative of having groups of mixed abilities 鈥 is that this practise is used in almost all secondary schools. Particularly in mathematics.鈥 He said the new analysis of TIMSS results found that 鈥渨hen the school uses achievement grouping, we do not see any clear evidence of substantial negative effects on disadvantaged pupil鈥檚 test scores, self-confidence or enjoyment of a subject. 鈥淚ndeed, if anything, tests scores of year 5 pupils may be very slightly higher when achievement grouping is used.鈥 Jerrim concluded that the results 鈥渄o not provide clear evidence that schools should necessarily be doing one thing (achievement grouping) or another (mixed-attainment grouping). 鈥淏oth have certain advantages and disadvantages, and it is best left up to school leaders to decide what is the right approach for their school. 鈥淏ut I do feel it is important that, when making this choice, they know that there isn鈥檛 strong evidence that 鈥 on average 鈥 achievement grouping harms the outcomes of pupils from disadvantaged social backgrounds.鈥