What are HA-QSARs ?
Often, the ultimate objective of the QSAR model is to prioritise chemicals for further testing rather than to predict an exact experimental value [...]. For this reason, it seems necessary to distinguish between QSARs created to provide approximations of experimental values and those specially designed to substitute for specific experimental endpoints, the HA-QSARs.

New Mechanism of Action definitions based on Molecular Initiating Events and a classification algorithm based on calculated stru
New MechoAs definitions and a corresponding classification algorithm.
We have developed this to replace Verhaar’s scheme and its limitations (ambiguous categories, restricted Applicability Domain) with an improved classification. This classification scheme for Mechanisms of Action (MechoAs) is required to be sure to use appropriate QSAR models when one wants to predict (eco)toxicity.