Paul LamereACM Recommender Systems 2012
Photo (CC) by Jason Rogers
I have 10 million songs in my
pocket.
Now what?
A recommendation that no human would makeThe challenge of music recommendation
You might like the Report on Pre-War Intelligence
If you like Britney Spears ...
WTF - Why the Freakomendations?The challenge of music recommendation
Why do we see such bad music recommendations?
Music is Special*
*of course every domain is special
Why do we see such bad music recommendations?The challenge of music recommendation
Understanding the domain is critical to the success of a
recommender
Why do we see such bad music recommendations?The challenge of music recommendation
10 things to consider when building a music recommender
10 things to consider when building a music recommender#1 - Very large item space
10 things to consider when building a music recommender#2 - Very low cost per item
10 things to consider when building a music recommender#2 - Very low cost per item
10 things to consider when building a music recommender#3 - Low consumption time
E Book Reader: Music subscriber:
Pew Internet Project.
24 books a year25 songs a day
The average song length is around 4 minutes
10 things to consider when building a music recommender#4 - Highly Interactive
A typical music recommender ...
... in 1999, but not anymore
10 things to consider when building a music recommender#4 - Highly Interactive
Today’s recommender
Recommendations are integrated into
the listening experience
10 things to consider when building a music recommender#4 - Highly Interactive
Today’s recommender
Minimal explicit feedback
10 things to consider when building a music recommender#4 - Highly Interactive
Today’s recommender
Much Implicit Feedback- Playing- Skipping- Repeating- Adjusting the volume- Sharing with friends- Adding to a playlist- Repeating the song- Inspecting song info
10 things to consider when building a music recommender#5 - Very high per-item reuse
songs[“as time goes by”].playcount += 1
10 things to consider when building a music recommender#6 - Large personal collections
There’s a long tail in my iPodPersonal Music Discovery Challenge
Listener Study
Listeners 5,000
Average Songs Per User 3,500
Percent of songs never listened to 65%
10 things to consider when building a music recommender#7 - Consumed in sequences
A good playlist is a balance of:
• Coherence• Familiarity • Discovery• Variety• Surprise
... in a pleasing order
10 things to consider when building a music recommender#8 - Highly contextual usage
10 things to consider when building a music recommender#9 - Highly passionate users
Let’s pause for a quiz
(ΔMī¹=αΣDi[n][ΣFij[n-1]+Fexti[[n ̄¹]])
Why is this formula troublesome for music recommendation and discovery?
Let’s pause for a quiz
(ΔMī¹=αΣDi[n][ΣFij[n-1]+Fexti[[n ̄¹]])
Why is this formula troublesome for music recommendation and discovery?
Because it is the name of a song by Aphex Twin
10 things to consider when building a music recommender#10 - OMG Metadata
The TheDuran Duran Duran!!!††† ///▲▲▲\\\▼□■□■□■
Various Artists
10 things to consider when building a music recommender#10 - OMG Metadata
The challengeMusic Taste is Irrational
Music I Like
Music You Like
Music I UsedTo Like
Get this t-shirt at dieselsweeties.com
Photo (CC) by Jason Rogers
Paul [email protected]@plamere
I have 10 million songs in my
pocket.
Now what?
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