"Discovery and search in social content sites "
Sihem Amer Yahia

An ever-growing number of users participate in social content sites such as Flickr, del.icio.us and YouTube, creating social ties and sharing content. Users come to these sites to find out about general trends -- the most popular tags, or the most visited content -- as well as for specific information, such as the recent activity of a friend or the most relevant content to a keyword search. We argue that users' tagging activity and social ties are indicators of their interest and should leveraged in these tasks.
I will talk about GUESTS, our ongoing effort in discovering social networks and content in del.icio.us. I will describe preliminary ideas on how to leverage users' shared behavior in recommending new content and the challenges behind using social networks to recommend and search user-generated content.