Journal ArticleDOI
Beware of q2
Reads0
Chats0
TLDR
It is argued that the high value of LOO q2 appears to be the necessary but not the sufficient condition for the model to have a high predictive power, which is the general property of QSAR models developed using LOO cross-validation.Abstract:
Validation is a crucial aspect of any quantitative structure-activity relationship (QSAR) modeling. This paper examines one of the most popular validation criteria, leave-one-out cross-validated R2 (LOO q2). Often, a high value of this statistical characteristic (q2 > 0.5) is considered as a proof of the high predictive ability of the model. In this paper, we show that this assumption is generally incorrect. In the case of 3D QSAR, the lack of the correlation between the high LOO q2 and the high predictive ability of a QSAR model has been established earlier [Pharm. Acta Helv. 70 (1995) 149; J. Chemomet. 10(1996)95; J. Med. Chem. 41 (1998) 2553]. In this paper, we use two-dimensional (2D) molecular descriptors and k nearest neighbors (kNN) QSAR method for the analysis of several datasets. No correlation between the values of q2 for the training set and predictive ability for the test set was found for any of the datasets. Thus, the high value of LOO q2 appears to be the necessary but not the sufficient condition for the model to have a high predictive power. We argue that this is the general property of QSAR models developed using LOO cross-validation. We emphasize that the external validation is the only way to establish a reliable QSAR model. We formulate a set of criteria for evaluation of predictive ability of QSAR models.read more
Citations
More filters
Journal ArticleDOI
Novel Approach to Strength Modeling of Concrete under Triaxial Compression
TL;DR: In this paper, a robust variant of genetic programming, namely gene expression programming (GEP), was utilized to build a prediction model for the strength of concrete under triaxial compression loading.
Journal ArticleDOI
Atom, atom-type and total molecular linear indices as a promising approach for bioorganic and medicinal chemistry: theoretical and experimental assessment of a novel method for virtual screening and rational design of new lead anthelmintic.
Yovani Marrero-Ponce,Juan A. Castillo-Garit,Ervelio Olazabal,Hector S. Serrano,Alcidez Morales,Nilo Castañedo,Froylán Ibarra-Velarde,Alma Huesca-Guillen,Alicia M. Sánchez,Francisco Torrens,Eduardo A. Castro +10 more
TL;DR: A novel atom-level chemical descriptor has been applied to estimate the anthelmintic activity and results suggest that the proposed method will be a good tool for studying the biological properties of drug candidates during the early state of the drug-development process.
Journal ArticleDOI
QSAR modeling using chirality descriptors derived from molecular topology.
TL;DR: It is shown that for all data sets 2D-QSAR models that use a combination of chirality descriptors with conventional (chirality insensitive) topological descriptors afford better or similar predictive ability as compared to models generated with 3D- QSAR approaches.
Journal ArticleDOI
VSMP: a novel variable selection and modeling method based on the prediction.
TL;DR: A novel variable selection and modeling method based on the prediction, for short VSMP, has been developed and a comparison of the results of the VSMP applied to the Selwood data set with those obtained from alternative algorithms shows the good performance of the technique.
Journal ArticleDOI
Advantages of support vector machine in QSPR studies for predicting auto-ignition temperatures of organic compounds
TL;DR: In this paper, a support vector machine (SVM) was used to develop quantitative structure-property relationship (QSPR) models for predicting auto-ignition temperatures (AIT) of organic compounds.
References
More filters
Journal ArticleDOI
Comparative molecular field analysis (CoMFA). 1. Effect of shape on binding of steroids to carrier proteins.
TL;DR: The main features of the CoMFA approach, exemplified by analyses of the affinities of 21 varied steroids to corticosteroid and testosterone-binding globulins, and a number of advances in the methodology of molecular graphics are described.
Book
Substituent constants for correlation analysis in chemistry and biology
Corwin Hansch,Albert J. Leo +1 more
TL;DR: In this paper, the book is the window to get in the world and you can open the world easily, and these wise words are really familiar with you, so bring home now the book enPDFd substituent constants for correlation analysis in chemistry and biology to be your sources when going to read.