CERTH @ MediaEval 2014 Social Event Detection Task

This paper describes the participation of CERTH in the Social Event Detection Task of MediaEval 2014. For Challenge 1, we use a“same event model”to construct a graph on which we perform community detection to obtain the final clustering. Importantly, we tune the model to have a higher true positive rate than true negative rate, leading to significantly improved performance. The F1 score and NMI for our best run are 0.9161 and 0.9818, respectively. For Challenge 2, we developed probabilistic language models to classify events according to the criteria of the different queries. Our best run on Challenge 2 achieved an average F-score of 0.4604.