Type of evidence | Description | How it contributes to knowledge |
---|---|---|
Theoretical | Ideas, concepts, and models used to describe the intervention, to explain how and why it works, and to connect it to a wider knowledge base and framework | Helps to understand the programme theories that lie behind the intervention, and to use theories of human or organizational behavior to outline and explore its intended working in ways that can be used to construct and test meaningful hypotheses and transfer learning about the intervention to other settings |
Empirical | Information about the actual use of the intervention, and about its effectiveness and outcomes in use | Helps to understand how the intervention plays out in practice, and to establish and measure its real effects and the causality of relationships between the intervention and desired outcomes |
Experiential | Information about people's experiences of the service or intervention, and the interaction between them | Helps to understand how people (users, practitioners, and other stakeholders) experience, view, and respond to the intervention, and how this contributes to our understanding of the intervention and shapes its use |