Archive for bad graphs

less-than-average illustration

Posted in Books, Statistics with tags , , , , , on June 7, 2013 by xi'an

This Sunday morning, I was reading the NYT when I came upon this picture illustrating Stephanie Koontz’s tribune “when  numbers mislead“, a rather dull summary of an unreferenced and impossible-to-google paper called “The Trouble With Averages” [what about Quételet?!] dealing with the impact of marriage(s) on happiness (and vice-versa). [Funny enough, Andrew was telling me about this economist from Warwick working on happiness just yesterday night!] I however wanted mostly to point out how a-statistical this picture was, from a meaningless Venn diagram (reminding me of Templeton!) to the notion of opposing average and variation, to outliers standing in the wrong place (intersection of whatever!). [I do not think it is relevant to stress the innumeracy revealed by the column and its title!]

A dubious statistic

Posted in Books, R, Statistics with tags , , , on June 1, 2011 by xi'an

Following a link on R-bloggers, I ended up on this page (with a completely useless graph that only contained the pieces of information 5% in 1900 and 55% in 2000). The author (Ralph Keeney) reports on “A remarkable 55 percent of deaths for people age 15 to 64 can be attributed to decisions with readily available alternatives.” This sounded to me like a highly dubious finding… So I looked at the paper itself, reading that

“A personal decision is a situation where an individual can make a choice among two or more alternatives. This assumes that the individual recognizes that he or she has a choice and has control of this choice. Readily available alternatives are alternatives that the decision maker would have known about and could have chosen without investing much time or money.” Ralph Keeney

This categorisation of deaths is highly debatable, in that choice is not always that available! So I do not see how the author can assert which percentage of the individuals truly have control of the choice… (For instance, can people refuse doing dangerous jobs when they desperately need a job? or when the dangerousness is an abstract concept as, say, for a Fukushima worker? Is obesity a sheer matter of will?) Furthermore, the jump from 5% to 55% is also highly shaky: “Clearly, one should not put much credibility in this 22% for 1950 or the corresponding 5% for 1900″.  In the end, tt seems that the whole issue of the paper is about the amount of information: “in 1900 the knowledge about and ability to avoid many of the causes of death would seem to be much lower than in 2000″. So life has not been getting more dangerous or people sillier, simply information about the causes of deaths has become more widespread. I am thus surprised at the low level of academic input contained in the paper (look at the “life-saving decisions’!), which may actually explain for the echo it found on the blogosphere. (This post also appeared on the Statistics Forum.)

Follow

Get every new post delivered to your Inbox.

Join 604 other followers