In experimental measurement of binding free energies, uncertainties on the order of 0.3 -0.5 kcal/mol for ∆Gexp and 0.4 -0.7 kcal/mol for ∆∆Gexp have been claimed from high-quality experimental measurements . It is, however, very often the case that experimental data are reported as single numbers, without quantification of the uncertainties. We have no knowledge about the statistics of ∆Gexp or ∆∆Gexp reported, let alone the distribution of these quantities. This means that the unknown and unstated error bars may be varying in all manner of ways, so claiming that they are normally distributed is not credible.