RECSYS

2009 is likely to become the "Year of the Netflix Challenge" in recommender systems. With a prize of one million dollars one of the highest in computer science, it raised a tremendous awareness for as well as a transformation to the field of recommender systems.

We are very happy to welcome you to the Third ACM Conference on Recommender Systems (ACM RecSys 2009) in New York. In the last few years, ACM RecSys has continuously grown and meanwhile certainly can be understood as the scientific core event in the area of recommender systems, bringing together persons from academic research, industry research as well as from applications. While recommender systems has close relations to many neighboring fields such as machine learning, information retrieval, databases, human computer interaction, e-commerce, semantic web and many others and many of the best conferences in these areas have their dedicated sessions on recommender systems, ACM RecSys is the conference where all of them finally meet.

With 187 submissions this year's ACM RecSys has continued to grow at a fast rate of over 50%. Authors from 35 different countries from all over the world submitted their papers. After the program committee consisting of 78 researchers finished a thorough scientific review process in two rounds writing almost 700 reviews, less than 19% of the long submissions have been accepted, the overall acceptance rate for long and short papers is less than 40%. Besides a deepened interest in algorithms for recommender systems, this year tags and social networks, privacy and security and trust attracted the most attention by authors.

Moreover, the program of ACM RecSys 2009 includes two keynotes, one from a more academic perspective and another one from a more industrial perspective, a panel session about the recently concluded Netflix challenge, three tutorials and three workshops as well as a doctoral symposium.