[Computational Complexity] When good recommender systems go bad!
- Lance brought up the question of amazon giving bad or odd here. The oddest pointer to an item I might want is as follows.
I bought a novelty CD by a group called Throwing Toasters (it was very good). I then was asked by amazone Do you want to buy a toaster? and got a pointer to home applicances.
Why did it make that association? Asking various computer people I got three answers. The only thing they had in common was that everyone was sure they were right.
- When many people buy an item the amazon software can do a reasonable data mining and make intelligent guesses about what groups of items go together. However, since this item was probably not bought by many people, it does a random word search algorithm instead.
- Of the few few people who bought this item before, some of them did buy toasters as well! So if only 4 other people bought this item, but 1 of them also bought a toaster, then WOW- 1/4 of all people who bought this item bought toasters, so its worth inquiring if the current purchaser wants one.
- Its a programming bug.
Posted By GASARCH to Computational Complexity at 2/27/2008 01:33:00 PM