Features

Netflix prizemaster made this announcement:

It is our great honor to announce the winner of the Netflix Progress Prize for 2007 to team KorBell (aka BellKor) for their verified just-in-time submission on Oct 1 at 23:29:20 UTC achieving an 8.43% improvement over Cinematch. We congratulate the team of Yehuda Koren, Robert Bell, and Chris Volinsky of AT&T Research Labs for their superb work integrating many significant techniques to achieve this result.

In accord with the Rules Yehuda and the team have prepared a system description paper, which we both make public below. We will be awarding the Prize in a presentation in at the Netflix offices in Los Gatos on November 19th, 2007 at 4pm. Yehuda Koren will present a public talk at that time about their Prize algorithm. We will post a video of that presentation via the Forum.

We have also updated the Prize leaderboard to reflect the award of the 2007 Progress Prize and have established the new accuracy requirement to qualify for the 2008 Progress Prize. Again, in accord with the Rules, the new Prize level reflects a 1% improvement over team KorBell's verified submission, requiring a 9.34% improvement over the original Cinematch accuracy level.

This Prize and, of course, the Grand Prize remain available to all qualified teams. We are pleased to note team KorBell continues to submit prediction sets as do many other teams. We look forward to everyone learning from what team KorBell has achieved and working to exceed the Prize levels. Good luck!

The KorBell paper submitted to the judges can be found below. This paper builds on, and requires familiarity with, several previous papers published by the team. Those papers are available below or via the team KorBell website.

R. Bell, Y. Koren, C. Volinsky, "The BellKor solution to the Netflix Prize", (2007).

R. Bell, Y. Koren, C. Volinsky, "Modeling relationships at multiple scales to improve accuracy of large recommender systems",
Proceedings of the 13th ACM SIGKDD international conference on Knowledge discovery and data mining (KDD'07), ACM Press (2007).

R. Bell, Y. Koren, "Improved Neighborhood-based Collaborative Filtering",
KDD Cup and Workshop (KDD'07), ACM Press (2007).

R. Bell, Y. Koren, "Scalable Collaborative Filtering with Jointly Derived Neighborhood Interpolation Weights"
IEEE Conference on Data Mining (ICDM'07), IEEE (2007).

Here is the Netflix official announcement.