Does the Index of Ideality of Correlation Detect the Better Model Correctly?

The CORAL software is a tool to build up predictive models for various endpoints by means of Quantitative Structure-Property/Activity Relationships (QSPRs/QSARs). A new criterion for assessment of the predictive potential of QSPR/QSAR models, so-called Index of Ideality of Correlation (IIC) is applied to improve the software. The ability of the IIC to detect models with better predictive potential is checked up with groups of random splits of data into the structured training set and extrenal validation set. To this end, two endpoints are examined (i) Toxicity towards Fathead minnow (Pimephales promelas); and (ii) drug load capasity of samples micelle-polymer. Applications of the IIC for endpoint represented by traditional Simplified Molecular Input-Line Entry System (SMILES) together with so-called quasi-SMILES has shown the suitability of the IIC be a tool to detect better model.