Probably because the item-based one prunes items from consideraiton by default. You'd have to provide a lot more information to say more.
On Tue, Oct 30, 2012 at 2:55 PM, yamo93 <[email protected]> wrote: > Hi, > > My input file contains more items than users, so according to the book > MAI, i expect that user-based recommendation is faster than item-based > recommendation but it's not what i see : item-based is 5 times faster. > > Here's some characteristics of my input file > Nb users:258 > Nb items:56756 > Nb lines:344816 > > Have you some explanations ? > > Thks, > Yann. >
