How Netflix’s AltGenre Movie Grammar Illustrates the Future of Search Personalization

I recently got sent this Atlantic article on how Netflix reverse engineered Hollywood by a few contacts, and it happens to mirror my long term vision for how Ranker’s data fits into the future of search personalization.  Netflix’s goal, to put “the right title in front of the right person at the right time,” is very similar to what Apple, Bing, Google, and Facebook are attempting to do with regards to personalized contextual search.  Rather than you having to type in “best kitchen gadgets for mothers”, applications like Google Now and Cue (bought by Apple) hope to eventually be able to surface this information to you in real time, knowing not only when your mother’s birthday is, but also that you tend to buy kitchen gadgets for her, and knowing what the best rated kitchen gadgets that aren’t too complex and are in your price range happen to be.  If the application was good enough, a lot of us would trust it to simply charge our credit card and send the right gift.  But obviously we are a long way from that reality.

Netflix’s altgenre movie grammar (e.g. Irreverent Werewolf Movies Of The 1960s) gives us a glimpse of the level of specificity that would be required to get us there.  Consider what you need to know to buy the right gift for your mom.  You aren’t just looking for a kitchen gadget, but one with specific attributes.  In altgenre terminology, you might be looking for “best simple, beautifully designed kitchen gadgets of 2014 that cost between $25 and $100” or “best kitchen gadgets for vegetarian technophobes”.  Google knows that simple text matching is not going to get it the level of precision necessary to provide such answers, which is why semantic search, where the precise meaning of pages is mapped, has become a strategic priority.

However, the universe of altgenre equivalents in the non-movie world is nearly endless (e.g. Netflix has thousands of ways just to classify movies), which is where Ranker comes in, as one of the world’s largest sources for collecting explicit cross-domain altgenre-like opinions.  Semantic data from sources like wikipedia, dbpedia, and freebase can help you put together factual altgenres like “of the 60s” or “that starred Brad Pitt“, but you need opinion ratings to put together subtler data like “guilty pleasures” or “toughest movie badasses“.  Netflix’s success is proof of the power of this level of specificity in personalizing movies and consider how they produced this knowledge.  Not through running machine learning algorithms on their endless stream of user behavior data, but rather by soliciting explicit ratings along these dimensions by paying “people to watch films and tag them with all kinds of metadata” using a “36-page training document that teaches them how to rate movies on their suggestive content, goriness, romance levels, and even narrative elements like plot conclusiveness.”  Some people may think that with enough data, TripAdvisor should be able to tell you which cities are “cool”, but big data is not always better data.  Most data scientists will tell you the importance of defining the features in any recommendation task (see this article for technical detail on this), rather than assuming that a large amount of data will reveal all of the right dimensions.  The wrong level of abstraction can make prediction akin to trying to predict who will win the superbowl by knowing the precise position and status of every cell in every player on every NFL team.  Netflix’s system allows them to make predictions at the right level of abstraction.

The future of search needs a Netflix grammar that goes beyond movies.  It needs to able to understand not only which movies are dark versus gritty, but also which cities are better babymoon destinations versus party cities and which rock singers are great vocalists versus great frontmen.  Ranker lists actually have a similar grammar to Netflix movies, except that we apply this grammar beyond the movie domain.  In a subsequent post, I’ll go into more detail about this, but suffice it to say for now that I’m hopeful that our data will eventually play a similar role in the personalization of non-movie content that Netflix’s microtagging plays in film recommendations.

– Ravi Iyer