SemEval-2015 Task 9: CLIPEval Implicit Polarity of Events Irene Russo author Tommaso Caselli author Carlo Strapparava author 2015-06 text Proceedings of the 9th International Workshop on Semantic Evaluation (SemEval 2015) Preslav Nakov editor Torsten Zesch editor Daniel Cer editor David Jurgens editor Association for Computational Linguistics Denver, Colorado conference publication russo-etal-2015-semeval 10.18653/v1/S15-2077 https://aclanthology.org/S15-2077/ 2015-06 443 450