Evaluating the impact of your public sector work is vital: it can help you to prove its value, attract extra investment and gain insights into how to improve as you scale up. We spoke to Elliot Trevithick, consultant at The Social Innovation Partnership (TSIP), to get his top tips and advice.

Always start with asking ‘why?’

By asking ‘why’ before getting into the ‘what’ and ‘how’, you can ensure that you start at the right place. Broadly speaking, there are two key purposes to evaluation: proving and improving. Proving is more externally focused, and is about showing what impact you’ve had to date. Improving is more internally focused: how can we do better going forward? How can we have even more of an impact?

Evaluate the right things at the right time

If your evaluation can cover both proving and improving, that’s fantastic. But if you don’t have enough resources to do both, then you should ideally prioritise one based on the development stage of your service or product. The earlier you are in the process, the more you should focus on improving, and vice versa. Whichever approach you take, remember that measuring impact shouldn’t just be about success or failure – it should be about empowering yourself to learn from your work, and showing your commitment to maximising your impact. Sometimes that will require you to have honest conversations with your key audiences about where you’re currently at, and how you get to where you want to be.

Use the ‘why?’ to think about ‘what?’

Revisiting the question of ‘why’ you are measuring impact can help you focus on how best to do it. What are you trying to achieve? What kind of data do you need to capture in order to see it? Would it be more compelling to demonstrate it using quantitative or qualitative data? For example, if it’s vital to show a particular funder how you have done in a certain area, you will need to focus on capturing that data accurately from the start. Or if you’re at an early stage of development, you may want to get informal feedback from staff to identify unresolved questions or problems that you could use as learning opportunities. Formal frameworks such as Nesta’s Standards of Evidence can provide you with ideas for different approaches that you might want to take.

Be realistic about what’s possible

It’s better to do a small amount of evaluation really well, than to do a lot badly! Keep the scope of what you’re doing realistic, and err on the side of ‘less is more’. Keep it lean. Decide how much you can cover based on the time and resources available, and focus on what is most important to you and your key audiences.

Make sure you get people on board

Relevant stakeholders, and especially your immediate team, need to understand why it’s important to evaluate your impact. Make time to talk together about what you want to get out of this exercise, ideally as part of an ongoing conversation where they share their feedback, input and views. You need everyone to understand why evaluating impact is a valuable thing to do if you’re to succeed.

Think about bringing in outside expertise

If you’re measuring your impact for the first time, you can pick up a lot of tips online. But it is worth doing it in the most informed way possible. This might mean bringing in extra resources and expertise. By working with an external partner, you can access valuable technical expertise about the practicalities and challenges of collecting and analysing data. An independent evaluation can also help to make the findings of your evaluation more authoritative.

Better late than never

It’s much better to start measuring your impact earlier rather than later. However, if that ship has already sailed, it’s still worth doing something retrospectively. In terms of proving, good robust case studies can provide powerful evidence of impact, particularly if conducted independently. If your focus is improving, you can still use surveys, interviews or focus groups to learn what worked well, what worked less well, and what you can do better in the future.