Guidance to better understand the how and why of social impact

A new how-to guide to evaluating the implementation of social interventions will drive greater knowledge of how we can best make a difference for people in need.

Developed by CEI with Youth Futures Foundation (YFF) and Dartington Service Design Lab, the guide to Theory-informed Implementation and Process Evaluation (TIIPE) offers step-by-step actions for evaluators, as well as practical, plain-language information for program commissioners and delivery partners.

“Within complex social service systems – whether youth employment, early years support or public health – outcomes are shaped as much by how programs are implemented as by what is delivered,” explains CEI Director, Dr Katherine (Katie) Young.

“While it is common practice for organisations to evaluate whether a program or intervention is effective in making change (or not), there are far fewer assessments of why things worked, how they worked, or whether they would work again elsewhere.”

“This can leave important questions unanswered: Why did something work in one place but not another? What adaptations were made, and how did these influence outcomes? And what would this program need to succeed at scale?”

TIIPE responds to this gap by bringing together program theory (what is meant to happen) and implementation theory (what actually happens in practice). This deeper evaluation yields more rigorous, detailed and nuanced evidence, that can better inform decisions on the targeting, adapting or scaling of effective approaches.

Framed as a reflective tool (rather than a rigid checklist), the TIIPE guidance will enable teams to make informed, context-sensitive decisions about evaluation design.

“Embedding theory-informed approaches to implementation and process evaluation will offer more actionable insights for improving delivery, greater transferability of learning across contexts, and stronger foundations for scaling and sustainability,” says Katie.

“Ultimately, TIIPE helps shift evaluation from a retrospective exercise to a tool for real-time learning and improvement that can lead to socially significant change.”

More about TIIPE and the new guidance

Theory-informed Implementation and Process Evaluation (TIIPE) is a structured approach to designing and delivering evaluation that integrates:

• Clear and testable theories of change
• Robust implementation science frameworks
• Iterative learning across different stages of program development

At its core, TIIPE encourages evaluators and delivery teams to move beyond describing implementation, towards explaining it.

This includes understanding:

• The mechanisms through which change is expected to occur
• The contextual factors that enable or constrain delivery
• The strategies used to support effective implementation

The TIIPE guidance provides a practical, stage-sensitive framework to support evaluation across the lifecycle of a program: from early development through to impact.

Included in the guidance are:

• Structured prompts and tools to articulate and test program theory
• Guidance on selecting and applying implementation frameworks, including CFIR and NPT
• Support for identifying and measuring key implementation outcomes (e.g. fidelity, reach, acceptability)
• Advice on integrating Implementation and Process Evaluations (IPEs) with impact evaluation, to strengthen causal inference

The TIIPE guidance is available HERE and the underpinning rapid evidence review HERE

Read a blog on TIIPE from YFF Head of Evaluation, Hannah Murphy HERE

Theory-informed Implementation and Process Evaluation Guidance was developed by Ediane Santana de Lima, Cristina Preece and Dr Julie Harris from Dartington Service Design Lab, current and former CEI staff Dr Stephanie Smith, Dr Gayatri Kembhavi-Tam and Jane Lewis, in collaboration with Jane Mackey and Hannah Murphy from Youth Futures Foundation.