All Things Data Science

Vorige week was er heel wat te doen rond een artikel van Tom F.M. ter Bogt, Loes Keijsers en Wim H.J. Meeus in het tijdschrift Pediatrics  over het verband tussen vroeg-adolescente muziekvoorkeuren en probleemgedrag. Ook in Vlaanderen maakte dit artikel veel ophef. Dit had onder andere te maken met een column van NV-A politicus Bart De Wever in De Standaard , waarin hij in een wat bizarre redenering dit onderzoek gebruikte om nogmaals zijn plaat over Theodore Dalrymple te draaien. Meteen was de toon gezet en ontstonden er twee kampen. Ten eerste had je de groep bestaande uit populaire kranten die een sappig verhaal konden presenteren en politici zoals Bart De Wever die de hierin de kans zagen om hun conservatieve opvattingen over cultuur empirisch te onderbouwen. Aan de andere kant had je de non-believers, die de wetenschappelijkheid van het onderzoek in vraag stelden of die morele bezwaren hadden. Gelukkig was er nog de krant De Morgen om het hoofd koel te houden. Ze sl...

Recently there was an interesting discussion on the Next Gen Market Research (NGMR) Linkedin group. The original discussion was started by Emma Kingham, Marketing Manager at Warc. She asked to "Make a prediction about the future of market research that you believe is GUARANTEED to happen". Pretty soon there was a subthread on market research and Big Data. Most of us agreed that the analytical capabilities you will find in the market research world can be valuable for Big Data, especially given the strong IT-leaning it seems to have. What we didn't agree on was, suprise suprise, the definition of Big Data itself.  Basically there were two schools of thought. One group saw Big Data as a relative concept: what is small for one community might be big for another. This school basically saw no difference between Big Data and Normal Data: It's just more of it. The other group, that included me, stressed the technical challenges (Hadoop, Mahout, and so on). In my view a lo...

We're about three weeks after the elections in The Netherlands but it seems like the discussion on the opinion polls is not finished yet. Especially in Belgium there is a lot of interest in the subject, probably because next week there will be municipal elections here. The general feeling in the media is that the accuracy of the polls in The Netherlands was not good. I tried to put the so called bad results in perspective by expressing the difference between a poll and the actual result in function of the sample size. You can find that blog post here . I would like to come back on this subject, after reading an article on Volkskrant.nl, the online version of De Volksksrant, a popular newspaper in The Netherlands.  If you speak Dutch you can read that article here . The title says that 9069 readers op Volkskrant.nl made a wrong prediction of the election results. There are a few remarkable things about this article. To start with, the winner, i.e. the participant who deviated th...

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 exc...

It's the holiday season, so we'll take a break from hardcore statistics and make way for a lighter note. Our sources tell us that Herman Van Rompuy, the European President, is secretly a huge Elvis Costello fan who is sending sublimal messages to promote his favourite Costello tunes. Can you spot which songs? Or do you think all of this is coincidental? You'll find the answers in the Comments section at the bottom of this post. Picture 1 Picture2  Picture 3 Picture 4  Picture 5  Picture 6 Picture 7 Picture 8 Picture 9  Picture 10 Picture 11 Picture 12 Picture 13 Picture 14 Picture 15 Picture 16 Picture 17  Picture 18  Picture 19  Picture 20 Picture 21 Picture 22  Picture 23  Picture 24

(Note: my apologies for this Dutch entry) In een opiniestuk in De Volkskrant op 16/07/2012 (zie http://www.volkskrant.nl/vk/nl/3184/opinie/article/detail/3286922/2012/07/16/Wantrouw-statistieken-negeer-peilingen.dhtml ) houdt de filosoof Hans Schnitzler ons voor dat we de statisticus moeten wantrouwen en de opiniepeiler negeren. Het is zijn goed recht om dat te doen. Er zijn, vooral in Nederland, de laatste tijd nogal wat persberichten verschenen rond opiniepeilingen die inderdaad de wenkbrauwen doen fronsen. Als Schnitzler ijvert voor grotere steekproeven en meer zorg voor representativiteit dan zal hij bij heel wat statistici en opiniepeilers op bijval kunnen rekenen. Meer zelfs, uitgerekend uit de hoek van opiniepeilers, en marktonderzoekers in het algemeen, is er een vraag om met meer zorg en nuance over onderzoek te rapporteren in de populaire pers. Als er al sprake is van een illusie van voorspelbaarheid dan wordt die illusie meer gevoed door de verslaggeving rond bepaalde o...