Crowdsourcing for the identification of event nominals: an experiment

This paper presents the design and results of a crowdsourcing experiment on the recognition of Italian event nominals. The aim of the experiment was to assess the feasibility of crowdsourcing methods for a complex semantic task such as distinguishing the eventive interpretation of polysemous nominals taking into consideration various types of syntagmatic cues. Details on the theoretical background and on the experiment set up are provided together with the final results in terms of accuracy and inter-annotator agreement. These results are compared with the ones obtained by expert annotators on the same task. The low values in accuracy and Fleiss kappa of the crowdsourcing experiment demonstrate that crowdsourcing is not always optimal for complex linguistic tasks. On the other hand, the use of non-expert contributors allows to understand what are the most ambiguous patterns of polysemy and the most useful syntagmatic cues to be used to identify the eventive reading of nominals.