All Things Data Science

The front page of "De Morgen" today (27/09/2012) features an article on public transportation and its relationship with road safety. The headline says "The less public transport, the more victims in traffic". To support this the frontpage shows a chart that I found difficult to understand. I had to look at it for several minutes before I understood what was going on. But I'll let you be the judge: First let me say that I applaud the fact that such an important subject is covered on the front page. Secondly, I'm always happy when I see that an article supported by statistical material is so prominent in the news. That said, there are quite a few problems with the chart: These circles represent the different statistics, however each has its own scale so that you need to be very careful how you compare them. The independent variables (different measures of public transport use in the cities)   are ordered from small to large, except the first one (percen

The 12th of September was election day for The Netherlands. A lot has been said on the opinion polls that were abundantly present in the media this year. Here are a couple of my thoughts. To start with, the media, or at least a part of it, was very quick in dismissing the polls. Peter Vandermeersch of the NRC newspaper tweeted that "the first casualties of the elections in The Netherlands were the polls. Can we stop with this now and forever?".  His reaction was remarkable in that he made it at 9.40 pm, at a moment when the actual results were not in yet. He must have based his reaction on ... the Exit Poll that was presented at 9.00pm. Another  thing that strikes me is that, unlike many other countries, The Netherlands has a tradition in reporting opinion polls in terms of the number of seats a political party will get, rather than simple proportions of the electorate. As a consequence, opinion polls are judged in terms of the number of seats they got wrong.  The excelle