We consider events as complex named entities, recursively consisting of simple named entities (people, places, organizations, dates, etc.) and/or other complex named entities. We have developed a processing chain dedicated to extracting, indexing and searching for social events in Web pages. In this context, we are proposing a generic similarity computation function that targets any type of complex named entity. In this paper, we implement this function according to three approaches which we shall describe and then experiment on a set of social events. \textcopyright 2017 Association for Computing Machinery.