Last autumn we shared early results of testing various versions of the GOV.UK 'Thank You' page. First introduced a year ago, people see this page once they've bought their tax disc via GOV.UK. People are generally more open to trying out new stuff after completing a successful transaction, so we've been using this page to encourage as many as possible to join the NHS organ donation register.
Over 350,000 people have now registered for organ donation via this one link on GOV.UK [since Jan 2013]
Via a comment on that earlier blog post, Claire reminded me recently that we'd not shared the final results of the experiment, notably which type of message was most effective at persuading people to register.
What we tested
Working with the Cabinet Office Behavioural Insights team, DVLA and NHS Organ Register team, we tested eight different calls to action with a total of over 1,000,000 visitors to the tax disc 'Thank You' page.
The eight variants below appeared at random, and we worked closely with the NHS Organ Donation team to see which one generated the most completed registrations. This is known as A/B testing.
What we found
Here are the results, showing which variant was most effective at getting people to actually register for organ donation. The percentages are not just for click-throughs; they're actual organ donor registrations.
The most successful variant introduced concepts of reciprocity and fairness by asking people: “If you needed an organ transplant, would you have one? If so please help others.”
I don't feel qualified to speculate as to the reasons why this particular message performs best - data trumps intuition. But, feel free to add your thoughts via the comments below.
We ended the experiment in the autumn, and have left this "reciprocity" message in place. Meanwhile, the new digital team at DVLA has got on with updating the tax disc service.
Since the DVLA tax disc online service is used by around 2m people every month, the impact of such optimisation is significant.
Extrapolated over 12 months, some 96,000 more people will register compared with the original call to action. ("Please join the NHS Organ Donor Register"). In December the former Cabinet Office Behavioural Insights team published a paper with more statistical detail on the experiment.
In total over 350,000 people have registered for organ donation via this one link on GOV.UK since we added the original call to action just over a year ago.
Stuff worth doing.