NPC's Four Pillars approach provides advice to charities and steps they should take to determine how to assess the difference they make.
Step one: Map your theory of change
A theory of change should be at the heart of your approach because it shows what you want to achieve and how you plan to achieve it, setting out the causal links between your activities and your end goal.
Step two: Prioritise what you measure
Your impact is likely to be diffuse, affecting different people in different ways. Prioritise the most important outcomes in your theory of change and focus on measuring those.
Step three: Choose your level of evidence
Choose an appropriate level of rigour of evidence that suits the needs of your stakeholders. This will depend on a combination of what is desired or needed and what is practical.
Step four: Select your sources and tools
You may be able to use existing data or tools, or you may need to develop your own. It is likely others will be measuring the same outcomes as you, so look at what already exists and assess its suitability.
Kazimirski, A., & Pritchard, D. (2014) Building your measurement framework: NPC's Four Pillar Approach. NPC New Philanthropy Capital