Some thoughts on Constituency Boundaries

4 Feb 2017 15:04 GMT

A few months ago I launched Constituency Boundaries, a small web app that lets you explore proposed changes to the boundaries of Parliamentary constituencies, which are being put forward as part of the 2018 Boundary Review.

I won't go over the details of how the app works here (the homepage explains it), but I wanted to set down a few thoughts about the process of developing this kind of software, because I think it has some interesting characteristics that put it somewhere between data journalism and traditional web application development.

Constituency Boundaries was developed primarily as a form of data journalism: to help answer a specific set of questions about a particular subject. The app exists because in the HoC Library we need a tool that not only allows us to compare the current and proposed constituency boundaries, but lets us explore how constituencies are composed, and discover what other possible arrangements of wards might produce alternative constituencies that also meet the boundary review criteria.

This requirement was essential, because if someone disagrees with some aspect of the proposed boundaries, it helps their case in the consultation process if they can show that a better alternative arrangement exists. (And making the app public means other people can use it for this purpose too.)

Because the app is designed to help people engage with a particular process, it doesn't have to be all things to all people. It's not a general tool for exploring theoretical arrangements of Parliamentary constituencies under every possible set of criteria; it directly addresses the questions raised by the 2018 review.

The development process was also journalistic in that the app was built to meet an event-driven news deadline — the announcement of the initial proposals for new constituencies — and to perform its role for the limited lifetime of that story, which concludes in 2018. This meant concentrating on core features and aiming for just a little more than the minimum viable product. The software is a living prototype rather than a fully evolved application.

And I'd argue that was the right approach because, as this chart from Mapbox's tile server shows, the peak of demand for the app was at its launch, on the day the initial proposals for England and Wales were published. So for this kind of software the features that matter are the features you can deliver on day one.

A chart showing a spike in website traffic at the time the app launched.

One way data journalism differs from application development is that you have more opportunity to iterate on your code between projects than within them. (Constituency Boundaries evolved from Population Builder, for example.)

At the same time, the deadline was known long enough in advance, and the boundary review process has a long enough lifetime, to make it worth some real effort. The app was built quickly, but relative to the features that it provides. It was more work than is involved in a simple interactive chart or map, and it needed additional development on the server.

I think there is a role in data journalism for small standalone data-driven apps like this: apps that expose large datasets to the public in a way that makes them explorable and easy to understand. They can yield more than one story. They can even move the story on.