Croatica Chemica Acta, Vol. 87 No. 3, 2014.
Original scientific paper
https://doi.org/10.5562/cca2402
Integral Sign Change Problem Check in Quantitative Structure-Activity/Property Relationships: A Tutorial
Rudolf Kiralj
; Technical College in Bjelovar, Trg Eugena Kvaternika 4, HR-43000 Bjelovar, Croatia
Abstract
Sign change problem (SCP) in multivariate Quantitative Structure-Activity/Property Relation¬ships (QSAR/QSPR) is the inconsistency in the direction of association between molecular descriptors and the dependent variable. Sign change is observed when the signs of the elements of the reference vec¬tor (correlation vector for the data set obtained from variable selection) are compared to the signs of the elements of all correlation and regression vectors related to a model. SCP check in this work, named Inte¬gral SCP (ISCP) check, is established to be a general effective anti-SCP procedure, consisting of five check levels. Twelve diverse QSAR/QSPR data sets from literature were tested, and performance of
data sets, models and descriptors was assessed by qualitative labeling systems. Most data sets
and models did not have satisfactory performance, what is discussed in terms possible data and model
remedy.
Keywords
sign change; direction of association between two variables; correlation; molecular descriptor; dependent variable; multivariate model
Hrčak ID:
130522
URI
Publication date:
18.11.2014.
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