Part-of-Speech is (almost) enough: SAP Research & Innovation at the #Microposts2014 NEEL Challenge

This paper describes the submission of the SAP Research & Innovation team at the #Microposts2014 NEEL Challenge. We use a two-stage approach for named entity extraction and linking, based on conditional random fields and an ensemble of search APIs and rules, respectively. A surprising result of our work is that part-of-speech tags alone are almost sufficient for entity extraction. Our results for the combined extraction and linking task on a development and test split of the training set are 34.6% and 37.2% F1 score, respectively, and for the test set is 37%.