For over a decade, drawing on their travel experiences, tourists have been using dedicated networks and social media sites to post comments, photographs, and reviews. This has resulted in a decline in the frequency of slideshows and travelogues perhaps, but such photographs and comments emerge from tens of millions of users and amount to hundreds of millions of elements of [Page 151]data available online. The size, complexity, and heterogeneous nature of this body of data present a challenge for analysts using traditional statistical and business analysis tools that are no longer relevant.

There is a need to turn to methods developed in the early years of the millennium that deal with huge datasets (massive data) or “big data”: cloud computing, data mining, graph analysis, knowledge discovery, ...