The idea that research should make a difference should not be controversial. But for some, the idea that you need to demonstrate that difference can be. Whilst the assessment of research impact is not new, over the past ten years it has become mainstream in a number of countries, including the UK, Australia and Canada, and is rapidly being adopted worldwide. This book is the story of one approach to understanding how research makes a difference. Sean Newell weaves an interesting tale that covers both the recent history of research impact assessment - in the UK and globally - and the development of researchfish, a tool that is fast becoming the international standard for research impact assessment.