*3.1. The Data Acquisition Module*

Information of interest to many cultural heritage applications are present in many different websites ranging from online encyclopedias like Wikipedia [66], online digital libraries like Europeana [67] or DBLP [68], to portals and directories like governmental sites on culture (e.g., Odysseus [69], the portal of the Greek Ministry of Culture and Sports) and WikiCFP [70]. However, presently, a lot of data/content of great interest to cultural heritage applications may be also discovered within popular social media like Facebook, TripAdvisor or Twitter. A vast number of people (of any origin, language or educational profile) have accounts in (typically more than one) social media

platforms, and use them to post their opinion about cultural heritage venues by publishing reviews, to describe their perceived experiences by uploading posts, to designate favorite destinations and provide useful points of interest (PoIs) by using "check-ins", or to keep up to date by subscribing to upcoming events hosted by different types of venues [71–73].

To cover this widespread need for data acquisition within the cultural heritage domain, Hydria provides a flexible yet powerful Data Acquisition module that is conceptually separated into two distinct submodules:

