Today I am starting work on a major new project, writing a book on data visualisation for the CRC-ASA series on statistical reasoning in science and society. There are several excellent dataviz books out there but I’m excited to be adding something new. This will be a brief, affordable overview that does not assume any previous training in statistics, or design, or coding. A lot of techniques will get described, but rather than just a baffling gallery, I want to make this a tour that shows the reader how to think through the options critically and justify their choices.
Procrastinating by taking a selfie in my secret hideout
The series should be a great collection for just this reason. More people than ever before have to work with data, and not all are experts or intend to be. I was inspired by the popularity of short, simple books on various business topics that you see in airport & railway station bookshops, and hope to provide something like that. I picture as my readers the manager in charge of risk analysis at a credit card company, or starting up a new modeling department in an insurance company, or the charity boss who wants to know what to ask for from the design team so their publications are more compelling (with apologies to any friends who see their own images there). You won’t see this in bookshops for a little while, but I’ll keep you posted on progress.
Some public lectures coming up soon that may interest anyone with a social/medical/political focus. These are at Conway Hall, Red Lion Square, London.
||Our Public Relations, their Propaganda
||8 Principles for successful optimists
||Prof David Healy
||The History and Future of Bioethics
||Prof Richard Ashcroft
||Preventative medicine? Are screening tests about science or politics?
||Dr Margaret McCartney
||The Ethics of Open Borders
||Prof Phil Cole
||Invisible England: Holding Therapy Practices in the UK
Thanks to Jay Ginn for posting these on the Radstats list.
Radical Statistics have now uploaded all the videos from this year’s conference and you can view them here. Themes were medical and financial mis-management of the figures, and there were some cracking good presentations, Aubrey Blumsohn’s being my favourite! Check them out.
Spotted at flowingdata.com
Nooooo! That’s not how it works.
This short animation by Jo Wood at City University aims to help us see the patterns in the mass of data arising from London’s bicycle hire scheme (often referred to as Boris Bikes, although the scheme was devised by the previous mayor Ken Livingstone). For those unfamiliar with this scheme, you can walk up to a bike rack, put in your credit card or pre-paid details, take a bike and then leave it at another rack somewhere else. Little trucks nip around the city redistributing the bikes to make sure they don’t all end up in one place.
At first glance I was baffled by the time aspect. What was changing over time? Were these real bike journeys at different times of the day? I was confused because I always click “play” before I read the text (also the reason why I can’t understand our TV remote control at home). Eventually I realised that it starts off showing all journeys, though the individual trails are simulated and not real people on bikes, and these accumulate over time until about 15 seconds in, when it gradually gets filtered down to showing the more popular routes and ends up with just the key “hubs” illuminated. Prof Wood says this is like “a graphic equaliser”, which is a concept much more familiar to my generation.
It’s a novel approach in quite a subtle way: time is used to show density. Imagine having loads of bivariate normal data and wanting to show the distribution. You could draw a contour plot but this gets nasty as the distribution gets more complex, so why not have an animation showing all the data in a scatterplot, and gradually remove the dots from the less populous regions, moving in by convex hulls until only the mode is still populated. Here’s a rough animation I made with uncorrelated bivariate normal data (n=10,000).
Now, for simple distributions like this, it’s not very useful. But when you get into weird shapes, it could be quite useful. Another way you could imagine it is a 3-D surface with density on the vertical axis, which gradually gets submerged below an opaque “water level” until only the highest peaks are visible.
Airing on 18 October 2012 on BBC4, there will be a new documentary on the role that chance plays in our lives, from the team that made The Joy of Stats. “Professor Risk” David Spiegelhalter will be presenting this time, clearly not put off by his previous TV role.
Prof Spiegelhalter was looking forward to decorating his Ford Capri