(Volume 2) ii Introduction This volume contains papers describing the CoNLL-2016 Shared Task and the participating systems. The 2016 shared task is on multilingual Shallow Discourse Parsing (SDP), and is a follow-on to the 2015 shared task. The languages covered in this shared task are English and Chinese. The SDP task involves identifying individual discourse relations that are present in a natural language text. A discourse relation can be expressed explicitly or implicitly, and takes two arguments realized as sentences, clauses, or in some rare cases, phrases. Shallow Discourse Parsing is a fundamental NLP task and can potentially benefit a range of natural language applications such as Information Extraction, Text Summarization, Question Answering, Machine Translation, and Sentiment Analysis.A total of 24 teams from three continents participated in this task, and 20 of them submitted system description papers. Many different approaches were adopted by the participants, and we hope that these approaches help to advance the state of the art in Shallow Discourse Parsing. The training, development, and test sets for English and Chinese were adapted from the Penn Discourse TreeBank (PDTB) and the Chinese Discourse TreeBank (CDTB) respectively. In addition, we also annotated a blind test set for each language following the PDTB and CDTB guidelines solely for the shared task. The results on the blind test sets were used to rank the participating systems. The evaluation scorer, also developed for this shared task, adopts an F1 based metric that takes into account the accuracy of identifying the senses and arguments of discourse relations as well as explicit discourse connectives. We hope that the data sets and the scorer, which are freely available upon the completion of the shared task, will be a useful resource for researchers interested in discourse parsing.As with the 2015 CoNLL shared task on SDP, participants did not each run their systems locally on the test set. Instead, they were asked to deploy their systems on a remote virtual machine and use a webbased evaluation platform called TIRA to run their systems on the test set. This kept them from seeing the data set, thus preserving its integrity and ensuring its replicability.We would like to thank all the participants of the 2016 Shared Task, as well as the program committee for helping us review the system description papers. Special thanks are due to the SIGNLL board members, Xavier Carreras and Julia Hockenmaier, for their support of the shared task over the last two years. We would also like to thank the PDTB team and CDTB team for providing annotated data for the shared task, and the Linguistic Data Consortium for their help with releasing the data to the participants. Special thanks go to Martin Potthast and the TIRA team, who provided their computing resources and more importantly their time in assisting teams to run their systems.
AbstractThe CoNLL-2016 Shared Task is the second edition of the CoNLL-2015 Shared Task, now on Multilingual Shallow di...