Thursday, April 28, 2016

What is science and what is politics?

In March 2009, the Spanish Directorate General of Traffic made the following announcement in the media: 22% of those who died in traffic accidents were not wearing seat belts. To save lives, everyone is recommended to use them.
Expressed in this way, the data are ambiguous. One might argue in this way: if just 22% of the victims were not wearing the seat belt, then a number over three times larger (78%) were in fact wearing seat belts when they died in an accident. Therefore it looks like it would better not to use the seat belt at all.
I’ll explain why this conclusion is fallacious. In order to draw the correct conclusion out of the data, one fact is missing: with or without accidents, how many people do use the seat belt and how many don’t? This piece of data can be found, although it took me some time and effort: 95% drivers do wear the seat belt, just 5% don’t. Combining this with the original data, we can compute the probability of dying in an accident with and without the seat belts: it is over 4 times higher among those who do not wear it than among those who do. If everybody used it, the number of deaths could decrease by 18%. Therefore the advice given was sound, although the data were incomplete.
Given how this news was presented, I feel moved to complain about the way in which politicians and the media use statistics and incorrectly report scientific data. If I do that, am I doing politics? Or am I defending science?

Thursday, April 21, 2016

Plans, forecasts and estimations

Forecast about energy consumption
The media, and sometimes even serious publications, often mistake the use of the three terms in the title of this post. In his book Small is Beautiful: Economics as if People Mattered (1973) E.F.Schumacher explains their differences:
We talk happily about estimating, planning, forecasting, budgeting, about surveys, programmes, targets, and so forth, and we tend to use these terms as if they were freely interchangeable and as if everybody would automatically know what was meant. The result is a great deal of confusion, because it is in fact necessary to make a number of fundamental distinctions. The terms we use may refer to the past or to the future; they may refer to acts or to events: and they may signify certainty or uncertainty.
According to Schumacher, combining the three different binary components (act-event; past-future; certain-uncertain) we have 8 possibilities:

Thursday, April 14, 2016

Crazy to predict the future

Consider this quotation of the book Small is Beautiful: Economics as if People Mattered (1973), by E.F.Schumacher:
There have never been so many futurologists, planners, forecasters, and model-builders as there are today, and the most intriguing product of technological progress, the computer, seems to offer untold new possibilities. People talk freely about 'machines to foretell the future'. Are not such machines just what we have been waiting for? All men at all times have been wanting to know the future.
These words are still true today, over forty years after they were written. What’s more, they apply especially to science and technology, two fields of human activity which at first glance should be free of fantasy and keep their feet glued to the ground.

Thursday, April 7, 2016

Is science higher than the arts?

Albert Einstein
The explosive expansion of Western science since the sixteenth century has led, with a delay of two centuries, to an equally explosive development of technology. In this situation, modern man tends to be swayed by appearances and thinks that science and technology are the most important of all human activities, as expressed in the quote attributed to Einstein:
One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike — and yet it is the most precious thing we have.
We could confront this paragraph against this quotation by E.F.Schumacher in his book Small is Beautiful: Economics as if People Mattered (1973):