This analysis shows a very strong correlation between chocolate consumption and intelligence; could we make a graph of those involved in this discussion? IQ scores vs. chocolate consumption? :P
http://www.nejm.org/doi/full/10.1056/NEJMon1211064 Kathy Darrow Phoenix, AZ On Oct 11, 2012, at 8:47 AM, ling huang wrote: > Re: 'BTW, for your story about the cat: In a statistical sense, the head > predicts the tail. Quite a difference from the head causes the tail.' > > Unless the cat is walking backwards. > > It is the word causation that is the problem. X is positively associated with > Y does not mean (and never means /or proves) X causes Y. Also note the need > for confidence bands and sample size determinations (or at least how many X,Y > pairs were used) in concluding there is even a relationship. How many years > and look at how much data was needed in the smoking/lung cancer relationship, > never mind causation. > > Ling > Ling Huang > Sacramento City College > > --- On Thu, 10/11/12, David L. McNeely <[email protected]> wrote: > > From: David L. McNeely <[email protected]> > Subject: Re: [ECOLOG-L] correlation v. causation > To: [email protected] > Date: Thursday, October 11, 2012, 6:27 AM > > ---- Miles Medina <[email protected]> wrote: > >> >> Also, I would add, in response to a comment above.. someone said >> correlation implies causation. Yes it may, of course, but let's not forget >> that there could be a third variable that causes the two correlated ones >> originally in question. > > I believe that the meaning of what was originally stated was that correlation > suggests a possibility, not that it implies or infers causation. Certainly > we all know about the false reasoning that allows us to believe in causation > due to correlation, when the relationship is simply coincidental. > > BTW, for your story about the cat: In a statistical sense, the head predicts > the tail. Quite a difference from the head causes the tail. > > David McNeely Wild About Wildflowers 25821 N. 41st Drive Phoenix, AZ 85083 623-582-1525 623-533-0171 (cell)
