NPC believes that donors should seek out the greatest possible impact when they make their giving decisions – it’s a fundamental part of our mission to help make that easier to do. But we also know that giving’s a matter for the heart as much as (and often more than) the head. As I’ve written before, here, research shows that there are at least six different types of donor behaviour. As much as NPC would like donors to do their research and seek the most effective charities, we know that in reality giving rarely works this way.

We also believe that charities should focus their communications to donors on the impact they create. As our paper Talking about results outlined, we think they can do that by answering the questions: What’s the problem we’re trying to solve? What do we do? What are we achieving? How do we know? How can we improve? But as that paper showed, most charities struggle to communicate the impact they’re having, and how they’re progressing against their big picture goals.

So if donors aren’t generally seeking out impact, and charities often aren’t communicating it, what can anyone do to try to nudge both sets of behaviour towards being more impact focused? We were excited to team up with the Guardian and Observer newspapers to help them design a 2010 Christmas Appeal that would work on both angles at once. In short, the mechanics of the appeal are built around charities’ ability to communicate their impact.

We asked charities to answer essentially the questions I pose above, and screened them on how well they did – how well they could talk about their results. The ten charities that got through the process are truly excellent organisations – making huge differences to the lives of the vulnerable young people they work with.

But when readers are moved by the stories they read, like this one about the huge challenges young carers face, and how one of the charities helps them to bring a bit of normality back to their extraordinary lives, they won’t give because of the structured and clear answers Action for Children gave in our application process. They’ll give because the stories they read inspire them, move them, and make them want to be a part of helping those young people.

So by working with the Guardian to build a selection process centred on how well charities talk about their results, we’ve been able to shift default behaviours of both charities and donors within this appeal. The charities that won do talk clearly about their impact. And the readers that give to the appeal are giving on the basis of communicated impact, they just don’t know it.

If you give to the appeal today or tomorrow (6th or 7th December) you’ll also double your donation through matched funding generated by the Guardian partnering with the Big Give. The Big Give’s model is an obvious winner – you give, and your donation’s matched by funding from a philanthropist or foundation – you double your money. Added to the exciting angle the Guardian and Observer appeal has taken by partnering with NPC to focus on charities that really talk about impact, I hope you’ll be inspired to give. A decision that works for both head and heart.