Abstract: Certain example embodiments relate to techniques for improving the effectiveness of a classifier. In one example, the classifier may be used to classify user reactions to an event such as, for example, a social media posting. The proposed techniques for improving the effectives of the classifier, in one example, automatically communicates with a verification platform to verify whether already classified user reactions are correctly classified, and when an incorrectly classified user reaction is detected, to determine an optimal negative indicator to be added to a list of negative indicators that is used by the classifier.