Internal and external validtions of QSAR model: Review
Li‐Tang Qin · Environmental Chemistry · 2013
Validation of a quantitative structure-activity relationship(QSAR) model plays an important role for ensuring the reliable predictive ability of activity of untested chemicals.Currently,a number of QSAR models,however,lack reliable validation.The present study reviews the internal validation and external validation methods that exist for QSAR model.The internal validations include leave-one-out(LOO) cross-validation,leave-many-out(LMO) or leave-N-out(LNO) cross-validation,y-randomization test and bootstrapping,while the external validations include the statistical parameters Q2F1,Q2F2,Q2F3,concordance correlation coefficient(CCC),r2m,and Golbraikh-Tropsha method.Furthermore,the cutoff values of the different statistical parameters for an acceptable model were recommended according to the references.The internal and external validations addressed in this study together with the recommended cutoff values of statistical parameters may help researchers to develop QSAR models.