Since 2011, the EEF has funded over 250 evaluations of education interventions in England. These trials — most of them randomised controlled trials (RCTs) — have involved more than 1.8 million pupils and made a significant contribution to the evidence base of what works to improve attainment and other outcomes in schools.
A rich resource for future learning
A key part of the EEF’s approach to evidence generation is making sure that data from our evaluations can inform future research. To support this, we archive the evaluation data at the end of each project. Hosted in the ONS Secure Research Service (SRS), the EEF archive is a goldmine of rich data from high-quality evaluations only accessible in a secure environment.
A key benefit of hosting in the ONS SRS is that archive data can be individually linked with other large administrative datasets, such as the National Pupil Database (NPD), to answer a range of questions. For example, this could be used to estimate long-term impacts of interventions, to understand variation in pupil outcomes, and to improve the evaluation methods we use.
We want to make data in our archive available for researchers to promote open science in education research, as well as to answer novel questions using innovative designs that advance evaluation methods. This will help us generate more evidence on what works, as well as to deliver stronger evaluations.
Enabling access through the Evaluation Accelerator Fund
Whilst the ONS SRS offers significant advantages in data security and in facilitating linkage with other administrative datasets, it also presents certain access challenges. For example, researchers are restricted from viewing the data variables or the completeness of the data sets prior to gaining access. This can make requesting the correct datasets and variables difficult, potentially meaning additional time and resources are needed.
This is why, in 2022, the EEF received funding from the Evaluation Task Force, a joint unit between the Cabinet Office and Treasury),and its Evaluation Accelerator Fund (EAF) to pilot access to our data archive and develop resources to support researchers to do so. A package of work was undertaken, which included:
- Development of a data catalogue by FFT, to showcase data available in our archive.
- Creation of synthetic datasets by Behavioural Insights Team (BIT) which uses a machine-learning technique to generate an artificial dataset that mimics the real data in the archive. This helps researchers to explore the data and generate analysis code prior to gaining full access to the data in the SRS.
Testing the process through two pilot research projects
To test access to our archive and learn how to improve the process, the EAF funding helped us to pilot two research projects. One project, led by a team at BIT, linked archive data with the NPD, the Higher Education Statistics Agency (HESA) and the Individualised Learner Record (ILR) to explore whether EEF-funded Key Stage 3 and Key Stage 4 interventions have lasting effects on post-16 attainment and progression. A second project, led by Oxford University, linked archive data with the NPD to examine whether pupils in EEF-funded trials were better protected against pandemic-related learning loss.
These pilots are helping to refine our processes for data access and lay the groundwork for future secondary analyses, with reports due to be published in early 2026.
New opportunities to use the EEF archive
We have just launched two funding streams using the EEF archive to support further evaluation work.
These are:
1. The methodological development grant aims to fund small-scale projects to improve research design and cost-effectiveness of our evaluations. These projects can use the archive data or other datasets.
2. The archive research projects fund aims to use EEF archive data to inform our understanding of programme impact, such as what works for whom and why.
Want to explore further?
If you are a researcher interested in secondary data analysis, the EEF Archive offers a unique opportunity. With access to high-quality trial data, you can contribute to a growing evidence base on how to improve education outcomes – and help us answer important questions about what works in education.
👉 Invitation to Tender: Using the EEF Data Archive to deepen our understanding of programme impact
👉 Explore the EEF data catalogue and appended low-fidelity synthetic data
👉 Read more about our archive here
👉 Learn more about how EEF is using synthetic data
👉 View all our latest invitations to tender