First stab at recommendations

I tried the most-obvious thing first, taking each reader, then each story s, then each of that reader's favorites f, and adding up how many times story s was favorited by other people who favorited f. Here are the recommendations for everyone who's tracking me.

It looks like it mostly recommends the same stories to everyone, just in a different order. I'm a little irritated that it wants everybody to read "Sweetie Belle Finds Out Where Babies Are Made," which I would not have picked as the best story on FimFiction. I don't know what's going on with "The Artifact", other than that it was very popular among the few who read it.

Also, it failed to recommend any stories by Bad Horse.

But it did a good job when I validated it! What I did was take each user, hold out 1/8 of their favorites, and see what the average predicted score was for those hold-outs (things they actually favorited), versus the average predicted score for that reader for all the hold-outs from all users. The score for stories that reader did in fact favorite, were on average 5 times as high as for stories that other readers favorited. [ADDED: Now I think that is a misleading artifact - the validation process is buggy.]

Do you like the stories on your list any better than the stories on the lists for other people (not counting things you favorited, which will not be on your list)?

People who list 1000 favorites - and a lot of people do - get lousy recommendations. The people who marked over 90 stories as favorites (Divinus Crepusculum, Magnumopai, Meta Knight), basically get back a list of the most-popular stories minus the ones they've already read.

Recommendations for Divinus Crepusculum
0.11152 The Artifact by primalcorn1
0.04899 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.03765 The Things We Leave Behind by theswimminbrony
0.02502 Secrets and Lies by SaddlesoapOpera
0.02329 Unintentionally Yours by JusticeSnake
0.02170 The Grey Factor by Japko
0.02153 Shipping and Handling by Pegasus Rescue Brigade
0.02124 My Little Alicorn by InsertAuthorHere
0.02078 Duties by Denim_Blue
0.01995 The Great Brony Migration by Laichonious
0.01972 On a Whisper of Wind by Conner Cogwork
0.01951 Better Living Through Science and Ponies by Pen Stroke
0.01619 Background Pony by shortskirtsandexplosions
0.01568 Luna's Student by MyWorld93
0.01530 Journey to my Imagination by DeiStar

Recommendations for Enthalpy
0.04384 The Things We Leave Behind by theswimminbrony
0.04320 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.02834 The Artifact by primalcorn1
0.02564 Shipping and Handling by Pegasus Rescue Brigade
0.02513 The Grey Factor by Japko
0.01970 Secrets and Lies by SaddlesoapOpera
0.01875 Smoke and Mirrors by TeaPartyCannon
0.01799 My Little Alicorn by InsertAuthorHere
0.01515 A Different Kind of Magic by Krizak
0.01364 A Lot Like You by Gravekeeper
0.01352 Better Living Through Science and Ponies by Pen Stroke
0.01274 Perfect For Me by The Equestrian Gentlecolt
0.01240 Sunny Skies All Day Long by PhantomFox
0.01206 On a Whisper of Wind by Conner Cogwork
0.01196 Duties by Denim_Blue

Recommendations for Feefers: No favorites

Recommendations for Hadles
0.00146 Beating the Heat by Andrew Joshua Talon
0.00139 Silent Ponyville 3 by JakeHeritagu
0.00134 Harmony by Aquaman52
0.00109 Everypony In This Town Is Crazy OR 'A shallow study on the mind of a fandom' OR 'When will you learn?!' by Lucefudu
0.00098 Shipping and Handling by Pegasus Rescue Brigade
0.00084 Secrets and Lies by SaddlesoapOpera
0.00073 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.00064 Eternal by device heretic
0.00062 The Best Night Ever by Capn_Chryssalid
0.00060 My Little Alicorn by InsertAuthorHere
0.00058 Shutdown by Cupcakes
0.00058 How to Woo Your Lady in Nine Easy Steps by paleowriter
0.00058 Unchangeable by TAW
0.00056 Sunny Skies All Day Long by PhantomFox
0.00056 Background Pony by shortskirtsandexplosions

Recommendations for Kavonde
0.00706 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.00398 Darn it, Pavlov! by DeltaMelon
0.00199 Magical Pony Ultrasounds by AbsoluteAnonymous
0.00121 Bureaucracy is Magic by Pen Stroke
0.00118 Background Pony by shortskirtsandexplosions
0.00053 Journey to my Imagination by DeiStar
0.00048 The Best Night Ever by Capn_Chryssalid
0.00047 Changing Octaves by Pen Stroke
0.00038 Secrets and Lies by SaddlesoapOpera
0.00036 Sunny Skies All Day Long by PhantomFox
0.00035 The Grey Factor by Japko
0.00027 Then You Saw Her by Possiblydominator
0.00026 The Judas Kiss by Voxis
0.00025 Keeping Your Hooves On The Ground by InsertAuthorHere
0.00020 And the Temptress Came Unto Her by device heretic

Recommendations for Magnumopai
0.09109 The Artifact by primalcorn1
0.07132 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.04245 The Things We Leave Behind by theswimminbrony
0.03062 Secrets and Lies by SaddlesoapOpera
0.02106 Shipping and Handling by Pegasus Rescue Brigade
0.01992 My Little Alicorn by InsertAuthorHere
0.01973 Unintentionally Yours by JusticeSnake
0.01940 Luna's Student by MyWorld93
0.01933 The Great Brony Migration by Laichonious
0.01742 The Ballad of Echo the Diamond Dog by Rust
0.01737 Background Pony by shortskirtsandexplosions
0.01722 Choices by Paleo Prints
0.01663 Better Living Through Science and Ponies by Pen Stroke
0.01611 Through The Eyes Of Another Pony by CardsLafter
0.01587 A Different Kind of Magic by Krizak

Recommendations for Meta Knight
0.13327 The Artifact by primalcorn1
0.05417 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.02471 Shipping and Handling by Pegasus Rescue Brigade
0.02327 Secrets and Lies by SaddlesoapOpera
0.02282 Luna's Student by MyWorld93
0.02044 Duties by Denim_Blue
0.01902 Better Living Through Science and Ponies by Pen Stroke
0.01645 Perfect For Me by The Equestrian Gentlecolt
0.01609 Choices by Paleo Prints
0.01528 Arrow 18 Mission Logs: Lone Ranger by AdmiralTigerclaw
0.01464 Then You Saw Her by Possiblydominator
0.01441 A Different Kind of Magic by Krizak
0.01427 Whip and Wing by Fernin
0.01257 Einhermare by Cosmonaut
0.01184 The Best Night Ever by Capn_Chryssalid

Recommendations for ponyaddict
0.06316 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.05877 The Artifact by primalcorn1
0.02573 The Things We Leave Behind by theswimminbrony
0.02394 Shipping and Handling by Pegasus Rescue Brigade
0.02285 Smoke and Mirrors by TeaPartyCannon
0.02175 Secrets and Lies by SaddlesoapOpera
0.02094 The Grey Factor by Japko
0.02037 My Little Alicorn by InsertAuthorHere
0.02036 Better Living Through Science and Ponies by Pen Stroke
0.01913 Background Pony by shortskirtsandexplosions
0.01738 Through The Eyes Of Another Pony by CardsLafter
0.01733 The Great Brony Migration by Laichonious
0.01721 The Ballad of Echo the Diamond Dog by Rust
0.01676 On a Whisper of Wind by Conner Cogwork
0.01676 Unintentionally Yours by JusticeSnake

Recommendations for protractor: No favorites

Recommendations for SheleKnights
0.07974 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.05708 The Artifact by primalcorn1
0.05502 The Things We Leave Behind by theswimminbrony
0.03349 Secrets and Lies by SaddlesoapOpera
0.02640 The Grey Factor by Japko
0.02381 Smoke and Mirrors by TeaPartyCannon
0.02157 Twilight's List by kits
0.02045 A Lot Like You by Gravekeeper
0.01843 A Different Kind of Magic by Krizak
0.01767 Magical Pony Ultrasounds by AbsoluteAnonymous
0.01752 Shipping and Handling by Pegasus Rescue Brigade
0.01728 My Little Alicorn by InsertAuthorHere
0.01664 The Great Brony Migration by Laichonious
0.01619 Duties by Denim_Blue
0.01611 Background Pony by shortskirtsandexplosions

Recommendations for Volkova
0.08631 The Artifact by primalcorn1
0.05329 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.03964 The Things We Leave Behind by theswimminbrony
0.03106 Smoke and Mirrors by TeaPartyCannon
0.02337 Secrets and Lies by SaddlesoapOpera
0.02029 Unintentionally Yours by JusticeSnake
0.01873 Give 'em the Old Razzle Dazzle by Shepard1707
0.01805 Luna's Student by MyWorld93
0.01773 Duties by Denim_Blue
0.01773 The Grey Factor by Japko
0.01722 Better Living Through Science and Ponies by Pen Stroke
0.01656 The Ballad of Echo the Diamond Dog by Rust
0.01575 The Great Brony Migration by Laichonious
0.01556 Choices by Paleo Prints
0.01522 A Different Kind of Magic by Krizak

Recommendations for wilce
0.05324 The Artifact by primalcorn1
0.04152 Sweetie Belle Finds Out Where Babies Are Made by TheOnly
0.03876 The Things We Leave Behind by theswimminbrony
0.02420 Unintentionally Yours by JusticeSnake
0.02342 Shipping and Handling by Pegasus Rescue Brigade
0.02225 Secrets and Lies by SaddlesoapOpera
0.02176 Perfect For Me by The Equestrian Gentlecolt
0.02090 A Lot Like You by Gravekeeper
0.02066 Duties by Denim_Blue
0.01787 A Different Kind of Magic by Krizak
0.01664 Smoke and Mirrors by TeaPartyCannon
0.01627 My Little Alicorn by InsertAuthorHere
0.01559 Choices by Paleo Prints
0.01532 On a Whisper of Wind by Conner Cogwork
0.01517 The Baker and The Scholar by Emerald Flight