The resulting stability constants (lg K) after optimisation are printed in Table , statistical judgements using SSE and SE y can be found in Table . The titration curve as well as the remaining absolute errors can be found in Fig. . The complex formation constants for the correct model differ only slightly from the initial ones. The easier 1:1 model estimates a lgK 11 that is too small, as happens upon fitting the 2:1/1:1 model. The most complex model resamples lgK 11 and lgK 12 , but the incorrect model parameter lgK 21 is realistic. Some of the chemical shifts in the 2:1/1:1 are smaller than zero (δ A 2 B,1 = -6.6334 ppm), indicating a change in the chemical shift up to 13 ppm (δ AB,1 = 6.5565 ppm). A full list of all parameters can be found in the example file in the SupraFit repository at GitHub. The "visual inspection" as described by Hynes, 9 can be performed using the charts in Fig. ) and 13(d), where all absolute errors are plotted in Fig. ) and the errors only from the 1:1/1:2 model and 2:1/1:1/1:2 model are plotted in Fig. 13(d). Clearly the 1:1 model perform worst, followed by the 2:1/1:1 model, with both having heteroscedastic errors. The remaining two models are optically indistinguishable with both errors being homoscedastic. † † Considering the resulting SSE, the decision towards the correct model can already be made, since SSE 1:1/1:2 ≈ SSE 2:1/1:1/1:2 and 3 • SSE 1:1/1:2 < SSE 1:1 . Comparing SSE of the fitted 1:1/1:2 model and the correct model show the slightly smaller error for the optimised model.