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Education Endowment Foundation:School uniform

School uniform

Unclear impact for very low cost based on insufficient evidence
Implementation costThe cost estimates in the Toolkits are based on the average cost of delivering the intervention.
Evidence strengthThis rating provides an overall estimate of the robustness of the evidence, to help support professional decision-making in schools.
Impact (months)The impact measure shows the number of additional months of progress made, on average, by children and young people who received the intervention, compared to similar children and young people who did not.

School uniform is the clothing that pupils are required to wear at school. Uniforms differ from the very formal and detailed (such as requiring blazers and specifying other items of clothing) to more informal and brief (such as involving just a school sweatshirt). Schools vary as to how strictly a uniform policy is enforced and whether it includes other aspects of pupils’ appearance.

1. The current evidence base on school uniform and academic outcomes is extremely weak. The limited evidence base means that an overall impact in months progress is not communicated.

2. Wearing a uniform is not, on its own, likely to improve learning, but can be successfully incorporated into a broader school improvement process which includes the development of a school ethos and the improvement of behaviour and discipline.

3. Staff commitment to upholding and consistently maintaining a uniform policy is crucial to successful implementation.

4. If a uniform policy is in place, it is important to consider how to support families that may not be able to afford uniform.

The lack of studies identified that tested school uniform approaches mean that there is not enough security to communicate a month’s progress figure. School uniform policies are often implemented alongside other improvement measures, which make it particularly challenging to measure the impact of uniform interventions alone. As a result, there is not enough security in the evidence to communicate a month’s progress figure.

There is a belief in some countries that school uniform supports the development of a whole school ethos and therefore supports discipline and motivation. Some also believe that a uniform promotes social equity. However, there is little robust evidence that introducing a school uniform will, by itself, improve academic performance, behaviour, or attendance.

There is a general belief in the UK that school uniform leads to improvements in pupils’ behaviour. It is important to remember that improved behaviour, on its own, does not necessarily lead to better learning, though it may be an important precondition (see Behaviour interventions).

Pupils from lower socioeconomic households are less likely to be able to afford the cost of school uniforms. Schools intending to change their school uniform policy should therefore consider what provision can be made to cover the costs of uniform changes for disadvantaged pupils.

School uniform policies are thought to complement the development and support of a whole school culture and approach, which in turn may assist pupil discipline and motivation.

Core components of a school uniform policy might include staff holding high expectations of pupils’ behaviour and that their attire reflects the values and culture of the school which the pupils reflect.

The implementation of a school uniform policy likely to be a significant cost for parents. It would not be advisable to change school uniform requirements regularly, as this may further disadvantage children and families of lower socioeconomic households.

The costs associated with introducing a school uniform are very low for a school, and mainly depend on parents buying the specified clothing instead of other clothes the child would wear. Some schools may subsidise or pay for the school uniform of children from low-income families, which is likely to slightly increase the cost associated with introducing a school uniform.

When introducing new approaches, schools should consider implementation. For more information see Putting Evidence to Work – A School’s Guide to Implementation.

There is extremely limited evidence on the impact of school uniform on attainment outcomes. For topics with extremely low evidence, a month’s progress figure is not displayed. Only 7 studies were found that met the inclusion criteria for the Toolkit. 

Evidence strengthThis rating provides an overall estimate of the robustness of the evidence, to help support professional decision-making in schools.
Number of studies7
Review last updatedJuly 2021