Plain old everyday Bayesianism!

Statistical Modeling, Causal Inference, and Social Science 2013-04-28

Sam Behseta writes:

There is a report by Martin Tingley and Peter Huybers in Nature on the unprecedented high temperatures at northern latitudes (Russia, Greenland, etc). What is more interesting is the authors are have used a straightforward hierarchical Bayes model, and for the first time (as far as I can remember) the results are reported with a probability attached to them (P>0.99), as opposed to the usual p-value

I agree. This is a good sign for statistical communication. Here are the key sentences from the abstract:

Here, using a hierarchical Bayesian analysis of instrumental, tree-ring, ice-core and lake-sediment records, we show that the magnitude and frequency of recent warm temperature extremes at high northern latitudes are unprecedented in the past 600 years. The summers of 2005, 2007, 2010 and 2011 were warmer than those of all prior years back to 1400 (probability P > 0.95), in terms of the spatial average. The summer of 2010 was the warmest in the previous 600 years in western Russia (P > 0.99) and probably the warmest in western Greenland and the Canadian Arctic as well (P > 0.90). These and other recent extremes greatly exceed those expected from a stationary climate, but can be understood as resulting from constant space–time variability about an increased mean temperature.

As with classical p-values, these probability statements depend on an assumed model, but I agree with Sam that the expression of direct probabilities is a huge step forward from traditional practice.