- Sky News special report on fracking 19 April 15
- The meaning of “correlation”
- Being conclusive
By Bill Butterworth
20 April 15
A special report on Sky News, 19 April 15, looked at a relationship between fracking and earthquakes in Texas. That report portrayed Professor Brian Stump, SMU University, Dallas, quietly saying that “there is undoubtedly a correlation between fracking and earthquakes”. The professor is an acknowledged expert seismologist. Not taking his statement seriously would be foolish. However, what does it mean?
Many years ago, when I was a student learning about statistics, it was pointed out that there is a correlation between the divorce rate in the UK and the rate of importation of wooden rolling pins. The point is that it is not difficult to find sets of figures which have similar patterns and therefore appear to be related. They might be. They might not be. What the word “correlation” does is to alert that there might be a relationship. To establish that there is a real connection, there has to be a logic or understood mechanism and there has to be evidence. When I used to do a great deal of work as an expert witness in court, if I wanted the judge to believe me, then I had to state a clear opinion, give a common sense explanation for that view and show evidence that is was true. The essence of scientific thinking is to have a hypothesis, have a logical explanation, and be able to test to provide evidence.
Looking back at the first post in this blog, dated 4 Jan 15, I looked at fracking and earthquakes. There is a logical explanation and it may be true. It is there in that first blog. I have gone back to it and thought about it.
Testing, however, is very difficult. I have no doubt that the professor and others are working on it. They will take time.