The 2011 Social Event Detection Task
This task requires participants to discover events and detect media items that are related to either a specific social event or an event-class of interest.

By social events we mean that the events are planned by people, attended by people and that the social media are captured by people. An event or an event-class of interest can be specified in terms of event-related metadata (e.g., location, time, venue, performers), example tags or other social information, example media items (images, videos), or a combination of the above. For example, an event of interest could be specified as “a concert given by a local band that took place in Barcelona during the first week of April 2010 and for which the following 5 pictures were taken”; an event-class of interest could be specified as “football games that took place in Roma in January 2011”. Five to ten such interesting happenings will be specified, differing in the level of granularity (e.g., specific event, general event-class) and in the information used for specifying them (e.g., location metadata, example media, etc.). The systems can use any combination of the available information (e.g., metadata, visual content, etc.) for detecting media items related to these interesting happenings within a pool of test data (images and videos accompanied by, possibly incomplete, metadata, social information etc.).

Target group
The task is of interest to researchers in the areas of information retrieval, multimedia content analysis, social media analysis, event detection and event-based multimedia indexing.

The data set comprises URL of images available on Flickr (~70k images), together with their accompanying metadata such as tags, time and location information, etc. (in an XML format).

Ground truth and evaluation
Ground truth information will record the true media-event associations and will be generated by the organizers. The results of event-related media item detection will be evaluated with F1 and normalized mutual information.

Recommended reading
Raphaël Troncy, Bartosz Malocha and André Fialho. Linking Events with Media. In the Open Track of the Linked Data Triplification Challenge, co-located with the 6th International Conference on Semantic Systems (I-SEMANTICS'10), Graz, Austria, September 1-3, 2010,

S. Papadopoulos, C. Zigkolis, Y. Kompatsiaris, and A. Vakali. Cluster-based Landmark and Event Detection on Tagged Photo Collections. In IEEE Multimedia, 2011.

Task organizers:
Raphael Troncy, Eurecom
Vasileios Mezaris, ITI Certh

This task is made possible by a collaboration of the following projects:

PetaMedia logoGlocal Project Logo