## 4 Results
### AD Definition during ML Model Deployment (Substudy 3)
The prediction errors of the new species vary depending on the splits, meaning that some species are better predicted in some splits than in others. In an attempt to assess the reliability of the predictions with respect to the AD, different visualizations are once again attempted in Figures 20-23. In particular, subfigures a and d of these figures display the standardized residuals vs. the _RF confidence_ anomaly scores of the training molecules and the new species of Split 1, for the enthalpy and entropy, respectively. Only the new species belonging to Cat. D--and some to Cat. C, in the case of the entropy--seem to have very low _RF confidence_ anomaly scores. Therefore, their predicted property values should have a high reliability, and this is effectively the case, as their standardized residuals are also very low. Note that in this work, the standardized residuals for the new species are available (except for some in Cat. C), but in real conditions, this would not have been the case. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Property** & **Category of Species** & **Split 1** & **Split 2** & **Split 3** & **Split 4** & **Split 5** \\ \hline \multirow{3}{*}{S} & A & 9 & 6 & 5 & 9 & 11 \\  & B & 0 & 0 & 0 & 1 & 1 \\ \cline{1-1}  & C & 26 & 23 & 26 & 23 & 33 \\ \cline{1-1}  & D & 25 & 19 & 20 & 20 & 24 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._Figure 19: Parity plots of the training molecules and new species for **entropy** for Split 1. Figure 18: Parity plots of the training molecules and the new species for **enthalpy** for Split 1. Figure 20: Visualization of the new species in **Cat. A and B** with respect to the AD of the **enthalpy** model for Split 1. Subfigures (**a**) and (**d**) show the standardized residuals vs. the _RF confidence_ anomaly scores, distinguishing training data and new species. The other subfigures show the tSNE 2D representation of the same data, distinguishing chemical families (color codes given in Figure A5) for subfigures (**b**) and (**e**), or distinguishing the reference H values for subfigures (**c**) and (**f**). Figure 21: Visualization of the new species in **Cat. C and D** with respect to the AD of the **enthalpy** model for Split 1. Subfigures (**a**) and (**d**) show the standardized residuals vs. the _RF confidence_ anomaly scores, distinguishing training data and new species. The other subfigures show the tSNE 2D representation of the same data, distinguishing chemical families (color codes given in Figure A5) for subfigures (**b**) and (**e**), or distinguishing the reference H values for subplots (**c**) and (**f**). Figure 22: Visualization of the new species in **Cat. A and B** with respect to the AD of the **entropy** model for Split 1. Subfigures (**a**) and (**d**) show the standardized residuals vs. the _RF confidence_ anomaly scores, distinguishing training data and new species. The other subfigures show the tSNE 2D representation of the same data, distinguishing chemical families (color codes given in Figure A5) for subfigures (**b**) and (**e**), or distinguishing the reference S values for subfigures (**c**) and (**f**). Figure 23: Visualization of the new species in **Cat. C and D** with respect to the AD of the **entropy** model for Split 1. Subfigures (**a**) and (**d**) show the standardized residuals vs. the _RF confidence_ anomaly scores, distinguishing training data and new species. The other subplots show the tSNE 2D representation of the same data, distinguishing chemical families (color codes given in Figure A5) for subplots (**b**) and (**e**), or distinguishing the reference S values for subfigures (**c**) and (**f**). Conversely, for the rest of the new species and/or for enthalpy, the _RF confidence_ anomaly scores are higher and the standardized residuals fluctuate significantly. For example, both very low (e.g., Cat. A or B for enthalpy) and very high (e.g., Cat. C or D for enthalpy, Cat. A or B for entropy) values are observed for the standardized residuals.