Cordis Bright are delighted to be working with the Youth Endowment Fund (YEF) and Media Academy Cymru (MAC) to evaluate the impact of the MAC Cerridwen programme in South Wales. The evaluation comprises an efficacy study with internal pilot including a randomised controlled trial (RCT) and implementation and process evaluation. The Cerridwen Programme aims to reduce violent behaviour and offending among young people through trauma-informed mentoring and cognitive behavioural approaches. Our evaluation will provide valuable insights into what works to improve outcomes for young people at risk and contribute to improving the limited evidence base about what works in reducing young people’s involvement in serious violence and offending.

About Cerridwen

The Cerridwen programme, delivered by MAC with funding from YEF, is a six-month intensive mentoring programme for young people aged 10–17 years at risk of violent behaviour or offending. Operating in Cardiff, Swansea, and Merthyr Tydfil, the programme uses cognitive behavioural approaches and trauma-informed mentoring to help participants build empathy, pro-social values, and emotional regulation skills, aiming to reduce offending behaviours and improve life outcomes.

Approach to the trial

Cordis Bright is conducting an independent evaluation of Cerridwen, structured as a two-arm parallel RCT with an implementation and process evaluation (IPE). The trial has been developed collaboratively with MAC and YEF through an extensive co-design phase. This phase included:

• Taking the MAC team with us on the evaluation journey including discussing the benefits of an RCT approach.
• Co-developing and testing a robust Theory of Change for the Cerridwen programme.
• Co-designing research tools, consent materials, and evaluation protocols.
• Co-designing an ethically robust approach that has been taken through the Royal Holloway University of London ethics process.
• Delivering training to case managers on evaluation processes and data collection.

The trial includes an internal pilot phase, followed by a full efficacy trial. Based on statistical power calculations and caseload modelling, it will involve 596 participants randomly allocated to intervention and control groups. Data sources include self-reported outcome measures, validated scales, programme monitoring data, police data, and qualitative interviews with young people, parents/carers, practitioners and other key partners.

The evaluation will generate insights into:

• The impact of the Cerridwen programme on a range of outcomes including: self-reported offending (primary outcome) and secondary outcomes such as offending measured by police data, and self-report measures of empathy, behavioural difficulties, pro-social values, and relationship quality with case managers.
• The effectiveness of trauma-informed mentoring and cognitive behavioural approaches in reducing youth offending.
• The barriers and enablers to effective implementation of the Cerridwen programme.

Key outputs

YEF have published the protocol for the trial, and further information about the programme. The study is also registered on the ISRCTN registry, a clinical trial registry recognised by WHO and ICMJE.

Next steps

The evaluation will run over two years, with interim findings from the pilot phase in early 2025 informing adjustments to the programme and trial methodology. Final efficacy reports in 2026 will provide robust evidence on the effectiveness of Cerridwen and contribute to the broader evidence base on interventions aimed at reducing youth violence and offending.

This research will play a vital role in shaping future practice and policy in youth justice, ensuring interventions are informed by rigorous evidence and the lived experiences of young people and practitioners.