[LINK] Netflix Prize

[stephen at melbpc.org.au]

And the Winner of the $1 Million Netflix Prize (Probably) Is …

By Steve Lohr  http://bits.blogs.nytimes.com/2009/06/26/and-the-winner-of-
the-1-million-netflix-prize-probably-is/?th&emc=th   June 26 2009, 6:51pm


After nearly three years and entries from more than 50,000 contestants, a 
multinational team says that it has met the requirements to win the 
million-dollar Netflix Prize:   http://www.netflixprize.com//index

It developed powerful algorithms that improve the movie recommendations 
made by Netflix’s existing software by more than 10 percent.

The online movie rental service uses its Cinematch software to analyze 
each customer’s film-viewing habits and recommends other movies that 
customer might enjoy. 

Because accurate recommendations increase Netflix’s appeal to its 
customers, the movie rental company started a contest in October 2006, 
offering $1 million to the first contestant that could improve the 
predictions by at least 10 percent.

Teams have been working on the task ever since, with some coming 
tantalizingly close to the magic threshold.

On Friday, a coalition of four teams calling itself BellKor’s Pragmatic 
Chaos — made up of statisticians, machine learning experts and computer 
engineers from America, Austria, Canada and Israel — declared that it has 
produced a program that improves the accuracy of the predictions by 10.05 
percent.  http://www.research.att.com/~volinsky/netflix/bpc.html

Under the rules of the contest, Netflix said that other contestants now 
have 30 days to try to do even better. If they cannot, BellKor’s 
Pragmatic Chaos will collect the $1 million.

The Netflix Prize contest has been hailed as prime example of "prize 
economics" and the crowdsourcing of innovation. Prize economics refers to 
running a contest to generate a new innovation at less cost than an in-
house research and development effort, and crowd-sourcing refers to using 
the proverbial wisdom of crowds to accomplish a task. Netflix has said 
that $1 million would be a bargain price for an improved recommendation 
engine, which would increase customer satisfaction and generate more 
movie rental business.

BellKor’s Pragmatic Chaos is a pretty elite crowd. The group is a 
collection of the 2007 and 2008 winners of the Netflix Progress Prizes — 
$50,000 a year for the teams that made the most progress toward the 10 
percent improvement — and a pair of engineers from Montreal who have long 
been near the top of the contest’s leaderboard.

  http://www.netflixprize.com/leaderboard

"What we’ve seen is that collaboration has taken hold," said Steve 
Swasey, a Netflix spokesman. "They realized how difficult the challenge 
is, and they have assembled people with complementary skills."

Mr. Piotte, a founder of Pragmatic Theory, explained why he recently 
joined the larger team. "Because of the nature of the competition, making 
a coalition of teams is a quick way to improve results,"he said in an e-
mail Friday night. "We felt that we had little chance to keep the lead 
against such a coalition unless we were part of one, too."

But he declined to say just how the team nudged their work over the 10 
percent threshold. "Since the competition remains open for 30 days, we 
are reluctant to disclose any secret at this time," Mr. Piotte said. "All 
I can say is that we all worked very hard to achieve this mark, and that 
the final solution contains many original ideas."

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Cheers,
Stephen. Ps, thanks Richard. As you know, have passed your response on.