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Research aims, methodology and terminology

This is a summary of the key findings and recommendations produced by a Rapid Evidence Assessment (REA), which aimed to explore and evaluate available evidence relating to the effects of reforms to school calendars, and alternative school calendars. The REA takes the form of a literature review, and examines evidence derived from 33 resources, including studies from Wales, the wider UK, and the USA.

The aim of the REA was to examine whether (and if so, how) changes to the school calendar and alternative school calendars, affected student learning, children’s health and wellbeing, the provision of wraparound care, and family life, as well as considering any other societal impacts caused by alterations to the school calendar.

The REA was carried out by Knowledge and Analytical Services (KAS) as part of a PhD internship, and aims to support the Welsh Government’s information gathering regarding optimum school calendars and potential changes to the school calendar.

Studies evaluated in this review focused on one of three interventions to the school calendar: year-round education (YRE), summer holiday provision, or extended school years.

The term ‘year-round education’ is used to refer to school calendars that feature changes which make terms and holidays more even in length throughout the year. Under a ‘single-track’ YRE calendar, all children attend school at the same time over the academic year (on a single ‘track’). Under a ‘multi-track’ YRE calendar, different groups of students attend school at different points over the academic year (on different ‘tracks’).

Main findings

The review found that often it was not possible to answer the research questions of interest as there were no studies that investigated these topics. The recommendations therefore focus on ensuring high quality, focussed evidence gathering and evaluation is built in to any proposed programme of school calendar change in Wales from the outset.

What evidence is there demonstrating effects and impacts of reforms to the school calendar, particularly in relation to learning, child mental health, physical health and wellbeing, wraparound care and family life?

There is mixed evidence as to whether YRE or summer holiday provision have produced positive effects on student achievement. Overall, research evaluated in this review indicated that extended school years did not produce positive effects upon achievement.

Limited evidence indicates that YRE delivered small positive effects upon child health outcomes, although many of these effects did not persist over the school year. There is mixed evidence as to the effects of summer holiday programmes, as several UK studies (two in Wales) reported associations between the examined programmes and positive child health and wellbeing outcomes, but two US studies found that a summer school programme did not produce positive impacts upon social-emotional outcomes for children, after one or two years of programming. The review did not find evidence regarding the impact of extended school years upon child health and wellbeing outcomes.

Limited evidence indicated that families of children attending single-track YRE schools were generally satisfied with the calendar and the process of transition. Five UK studies (two from Wales) demonstrated summer holiday programmes were associated with improved wellbeing, reductions in stress and financial pressures for parents, and increased quality time for families. This review did not find any studies that examined the effects of extended school years upon family life. No studies were found that explored the impact of changes to the school calendar upon the provision of wraparound care.

Are specific impacts upon disadvantaged and/or other groups of learners examined or identified? What are they? How do alternative calendars impact provision for students with Additional Learning Needs (ALN), and the learning and wellbeing of those students?

Evidence reviewed here generally indicates that neither YRE nor summer holiday provision significantly narrowed the attainment gap between economically disadvantaged students and their non-economically disadvantaged peers. Some very limited evidence indicates that disadvantaged students in particular experience improvements in their confidence, school readiness and socialisation, as a result of attending summer school. Evidence as to the impact of extending the school year upon students from economically disadvantaged backgrounds was very limited but positive, as one study found positive effects upon the achievement of students from economically disadvantaged backgrounds.

The evidence evaluated here indicated, overall, that single and multi-track YRE did not consistently affect the academic attainment of students from Black, Asian and Minority ethnic communities differently to the academic attainment of white students. This review found no studies that explored the impact of summer holiday provision or of extended school years upon students from ethnic minority communities.

There is some very limited evidence to indicate an association between summer school programmes and improved school readiness among looked after students. The review found no studies that considered whether YRE or extended school years produced particular effects on looked after students.

Some very limited evidence indicated that summer holiday provision did not assist students who are struggling academically in catching up. The review found no studies that explored whether YRE or extended school years impacted academically struggling students differently to other students.

The review found no studies which examined whether changes to the school calendar impacted students differently on the basis of students’ sex.

Findings were mixed as to the effects of YRE upon students with ALN. Evidence regarding the impact of summer holiday provision upon students with ALN was very limited. A study from Wales reported that provision had been associated with reduced stress in attending children with ALN. This review found no studies that explored the impact of extended school years upon students with ALN.

What evidence is there of alternative calendars being applied or considered in contexts where language immersion, or intensive language learning, is a feature of education provision? How have these considerations been approached in the planning and delivery of the alternative calendars? What are the effects of alternative calendars on this feature of provision?

None of the studies reviewed here examined the impact of changes to the school calendar upon Welsh-medium provision in education, or upon education systems that feature language immersion or intensive language learning in existing provision. Parents in one study reported that their child’s attendance of summer provision had assisted them in maintaining their Welsh language skills. The review found no studies that examined the effects of YRE or extended school years upon Welsh-speaking students.

Studies reviewed here did not indicate that students who speak English as an additional language (EAL), in particular, experienced positive impacts upon their academic attainment as a result of YRE or summer holiday provision.

What other effects have been demonstrated or suggested?

Limited evidence indicated positive effects of YRE and summer/holiday programmes upon teachers and other school programme staff. The review did not find any studies that examined the effects of extended school years upon teachers or other school staff.

Evidence as to the impact of YRE and summer holiday provision upon student behaviour was limited and mixed. There was limited evidence to indicate that extended school years produced negative impacts upon student behaviours among 13 to 14 year olds, but did not affect the behaviour of 9 to 10 year olds.

Although only two studies examined economic impacts, both concluded that YRE produced small (but significant) negative economic impacts. House prices and maternal employment rates were found to be lower in the catchment areas for schools that had YRE calendars. Reasons for this were not explored as part of the research. The review found no studies that examined the economic impacts of summer holiday provision or of extended school years.

What factors have led to these reforms? Have these reforms been accompanied by wider changes (for example changes to the number of teachers, or changes to the curriculum)? If so, what are these changes? Have these reforms been made specifically in response to the COVID-19 pandemic?

Studies included in this review did not identify factors that had led specific schools or districts to reform their school calendars. However, a number of researchers commented that, while single-track YRE was generally adopted to improve academic achievement and reduce summer learning loss, multi-track YRE was more commonly adopted to combat the effects of overcrowding in schools.

Researchers examining summer holiday provision tended to identify the aims of these programmes, rather than factors involved in deciding to implement them. The majority of these programmes aimed to maintain or improve the health and wellbeing of children, particularly those from disadvantaged backgrounds.

In examining the effects of altering the length of the school year, researchers did not specify particular factors for these alterations in specific schools or districts. However, some researchers noted that extensions to the school year were often adopted with the aim of improving academic achievement.

The majority of studies in this review did not specify whether reforms to the school calendar were accompanied by broader changes to schooling.

No studies in this review indicated that the reforms to the school calendar were made in response to the COVID-19 pandemic.

How have reforms been implemented? In particular, what changes to funding arrangements, workforce volume and structure, incentives or statutory requirements have been deployed or considered?

Although some of the studies included in this review did provide some details as to how alternative school calendars were implemented, the review found no studies that detailed changes to the volume or structure of the workforce, or of any incentives or statutory requirements being used or considered.

Some studies did provide details of certain aspects of implementation, particularly studies that examined summer holiday provision. These aspects included the costs of delivery, the structures and organisations involved in planning and delivering provision, and the duration of provision.

What barriers and facilitators have been encountered and what have been their effects?

This review found little available evidence as to the barriers to and facilitators of implementing YRE. Teachers in one study recommended the use of smaller class sizes, ensuring that students were taught by their usual teacher, and ensuring that ‘remedial’ lessons delivered during intersession weeks are engaging and different to ‘normal’ lessons. Intersession weeks are a break between the traditional academic term in which students undertake educational activities in school. These activities may focus on key areas of learning to assist the student to ‘catch-up’ with peers, or could involve non-academic activities.

Many studies that examined summer holiday provision reported on the barriers to and facilitators of delivering effective programmes. Reported barriers included low attendance, difficulty identifying and targeting students from disadvantaged backgrounds, costs and insufficient staffing. Staff expertise and experience, early planning, and effective collaboration with schools and other organisations were identified as facilitators.

The review found little available evidence regarding barriers to and facilitators of implementing extended school years. Directors of special education in Texas reported difficulty finding qualified staff who would work over the summer period as the most common barrier to providing extended school year (ESY) services to students with ALN. This appeared to be a greater problem in rural areas. Other barriers reported by directors were determining the eligibility of students for ESY services, gaining support from parents, and a lack of financial resources. Directors in rural areas reported significantly more barriers than directors in non-rural areas.

Another study examined the impact of challenges in determining the eligibility of students with ALN for ESY services. Analysis here suggested that the way in which eligibility was determined kept students with ALN from accessing appropriate ESY provision.

The effects of reported barriers and facilitators varied across studies; not all researchers explicitly detailed the effects of these barriers and/or facilitators.

What is the nature of the activities provided within alternative calendars, outside of class teaching? What is the balance between class teaching, learning support activities, individual tuition, physical activity and creative/cultural activity in alternative calendars, and what are the effects of these allocations of activities? Who delivers these activities?

The majority of studies included in this review did not examine the content or nature of the activities provided by schools that had adopted YRE calendars, or who delivered these activities.

Some researchers discussed the content and the nature of the activities that students undertook when they attended summer holiday provision. Researchers from three studies reported that attending students received instruction in literacy (or language arts) and numeracy every day during provision, and spent between approximately 150 minutes and half a day studying these subjects. The researchers from these three studies reported that the programmes they studied also contained enrichment activities. Other studies that evaluated summer holiday programmes provided some detail as to the types of activities that were offered during provision.

Studies included in this review did not explicitly consider the effects of the balance between different types of content, and how content was allocated within summer holiday provision. However, some studies did consider the effects of particular types of content upon children attending provision. A report summarising available evidence on summer schools stated that in order for a summer school to positively impact students’ academic achievement (including students from disadvantaged backgrounds), it must feature an academic component. In addition, a study examining the effects of a summer programme in Wales found that several specific elements of the programme were perceived by programme staff, parents and/or children to have produced positive impacts on attending children, such as improved wellbeing for the children that attended, and a reduction in family stress.

Some researchers discussed who was responsible for delivering summer holiday provision. However, most studies did not explicitly consider how the personnel responsible for delivering provision could influence the effectiveness of the summer holiday provision. One report, summarising existing evidence regarding summer schools, stated that where summer schools were delivered by teachers already familiar to the students, these schools produced approximately four months of additional learning gains on average, one month more than the average impact of summer schools upon learning generally.

Some studies also detailed the student-to-teacher ratio and/or class sizes of certain summer holiday programmes. However, very few studies detailed the effects of the student-to-teacher ratio or group sizes upon the effectiveness of provision. A report which summarised existing evidence regarding summer schools stated that summer schools which featured teaching in small groups or on a one-to-one basis tended to produce higher average impacts, and that in order for disadvantaged children to benefit from a summer school, the summer school would need to feature ‘small group’ or ‘one-to-one’ teaching.

This review found no studies that explored the content or the nature of activities delivered during extended school years, or who delivered content and/or activities during extended school years.


Due to the mixed and inconclusive nature of the evidence identified in this review, it is recommended that any proposed programme of school calendar change in Wales should incorporate high quality and thorough evidence gathering, at all stages, from planning and consultation stages, through to setting out a clear rationale, and to assessing implementation and impact.

Full and thorough engagement and consultation are recommended. This will allow the very broad range of groups affected by these changes to articulate what the potential impacts might be, will reveal effects not anticipated by policy makers, and will help ensure that robust monitoring and evaluation activity explores what matters to these groups. The views of groups who may not usually readily participate in this type of activity should be sought as a priority.

It is recommended that the reasoning and logic behind any proposed changes to the school year be clearly set out. This should include details of anticipated outcomes, including benefits such as  learner progress, attainment, health and wellbeing, practitioner health and wellbeing and workload and family life, and the economy. How and when these outcomes and benefits are expected to manifest themselves, and how they will be evaluated, should also be given explicit consideration and clearly described.

An evaluation programme which seeks to establish baselines in relation to the factors that changes will impact upon, and to include monitoring and evaluation of these factors to confidently understand their effects, is recommended. There was no reliable available evidence regarding the effects of changes to the school calendar upon key groups/areas of interest, such as childcare providers, the provision of wraparound care, Welsh-medium provision in education, and Welsh-speaking students. Additionally, there was limited evidence in relation to a number of outcomes, as outlined in the key findings. The effects of reforms upon these groups/areas should be of key concern.

Lastly, as this review found that many published articles do not contain specific details of implementation, it is recommended that policy-makers explore whether officials who have implemented reforms in this area would be willing to provide more information directly to Welsh Government.

Contact details

Report Author: Siân Hughes

Views expressed in this report are those of the researchers and not necessarily those of the Welsh Government

For further information please contact:
Schools Research Branch

Media: 0300 025 8099

Social research number: 5/2022
Digital ISBN: 978-1-80391-561-6

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