In the previous article we looked at a psychological study which claims to provide evidence that certain types of extra-sensory perception exist, using a statistical method called significance testing. But do the results of the study really justify this conclusion?
In March 2011 a highly respected psychology journal published a paper claiming to provide evidence for extra-sensory perception (ESP). The claim was based largely on the results of a very common statistical procedure called significance testing. The experiments provide an excellent way into looking at how significance testing works and at what's problematic about it.
How many people died? It's one of the first questions asked in a war or violent conflict, but it's one of the hardest to answer. In the chaos of war many deaths go unrecorded and all sides have an interest in distorting the figures. The best we can do is come up with estimates, but the trouble is that different statistical methods for doing this can produce vastly different results . So how do we know how different methods compare?