where Σ α = (αE +S T W S ) -1 , and Σ α,kl are the elements of this matrix. However, the same application of the uncertainty calculation (Equation ) will give untrustworthy values because the regularization term will artificially reduce the uncertainties. To get more reliable estimates of the uncertainties, we may use the approach from Ref. . In this case, we extrapolate the experimental uncertainties based on the second derivatives of the parts of the least-squares functional 18, in particular, a