If you already know what difference you make – and you can prove it – this guide is not for you. And if you are an experienced evaluator with an understanding of cost-benefit analysis, you will find it too basic. (Have a look at The Guide to Social Return on Investment instead). But if you want to understand more about how your organisation makes an impact – and how much this matters – then read on. This guidance was produced with Social Value UK members Hall Aitken.