mySociety design tips: avoiding duplicate messages


One of the common elements you will find across mySociety’s sites is that they have features designed to reduce duplicate messages or reports being sent to politicians, governments or companies. We often do this in quite a subtle way, so it is worth spelling out here how we do this across several sites:

  • If you start to report a broken street light or pothole on FixMyStreet, you’ll see local problems before you start to type in your own details. This means if the problem is already there, you can see before you waste any effort.
  • If you use WhatDoTheyKnow to send a Freedom of Information request to a public body, we provide a facility which encourages users to search through other people’s requests before they type their new request in.
  • If the 08:10 train you take to work is always late, when you go to report it on FixMyTransport, we show you all the other problems already reported on that route. If someone else has already set up a page, you can press the big green ‘join’ button, and show your support.
  • If more than a handful of people try to use WriteToThem to send an exact duplicate of the same message to a politician, it will prevent it. This is because we know that politicians listen much, much more to individual messages from constituents than bulk mails.

This pattern – trying to intervene before people write identical messages or reports – is a design decision that makes a big difference to the way these sites operate. As usual with mySociety sites, this little feature seems like the sort of thing that would be quite tempting to skip when building a copy. But it really matters to the long term success of the sites. There are three reasons why.

First, there is a simple public benefit that comes from saving time. There’s no point us wasting your time if a report or request has already been sent, especially around minor issues. Saving your users time makes them happier and more likely to enjoy their experience.

Second, if you can spot that someone is about to send a duplicate message, we may be able to encourage that user to support the existing report instead of making a new one. For example, on FixMyStreet you can add an update to an existing pothole report (“it’s getting worse!”).

This feature is most visible, and most mature, on FixMyTransport, where users are clearly encouraged to ‘support’ pre-existing reports, rather than making new copies.  By discouraging duplicate reports, we let people with a shared problem work together, even if this only means adding themselves as a “supporter” and doing nothing else. We know that many people search for, and find, problem reports which have turned into these little campaigns, which they then join and help. So even if they are only reading them (not joining them) that exposure can have some value to the people affected. This would be diluted if we created lots of similar reports about the same problem.

Third, we discourage duplicates for the benefit of the governments and companies receiving messages. We don’t think FixMyStreet is effective because it lets people moan: we think it’s effective because it helps local government to be effective by giving them good quality reports about local problems, in formats that area easy to handle. This good quality reporting increases the chance that the government will understand the problem and act on it, which leads to our main goal – citizen empowerment. Recipients are unlikely to help users if many of the messages they get are confused, inaccurate or duplicates, so we work on all these fronts.

So if you haven’t thought about this before, notice how the “work flow” through our sites makes you see similar problems before you’ve finished reporting your own. This is the implicit way to prevent duplication. We don’t have “Stop! Warning! Check this is a new problem!” messages, because we never want to discourage genuine users. But the careful design of the interface gently discourages, successfully, duplicate reports, and encourages supporting of other items.

It’s never possible to entirely prevent duplication. But we try hard, because it’s always better to join people together around common causes, than it is to let them struggle alone.