Yes, and there is no assumption here that the item is vastly popular. The proposal was to drop any user-item interaction where the item was the only one rated by the user, whether the item is popular or not. There's a non-zero, and probably non-trivial, affect on correctness as a result.
On Fri, Dec 2, 2011 at 6:18 PM, Ted Dunning <[email protected]> wrote: > On Fri, Dec 2, 2011 at 10:14 AM, Sean Owen <[email protected]> wrote: > > > I agree, though that's something slightly different to the question at > hand > > here. If just about every user viewed X, you could probably forget X, > yes. > > > > But if some user happened to only view one item, Y, can you drop that? It > > affects correctness. I argue that it doesn't really affect the bottleneck > > in question here, which is not quite the point you are getting at. > > > > No. Dropping that does not affect correctness if that item is highly > popular. > > If that item is not vastly popular, it does provide some information and > would not be affected by my suggestions. > > > > > > On Fri, Dec 2, 2011 at 6:07 PM, Ted Dunning <[email protected]> > wrote: > > > > > Since touching them adds nothing but cost, then not touching them is > > > better. Kill the item! > > > > > > In practical terms, we had this problem at Veoh. Everybody got the > same > > > intro video. It provided no information. Likewise at Musicmatch, > > > everybody got the same startup noise during the splash screen. It > added > > no > > > information. Both of these cases would kill performance in lots of > > > recommendation engines because a vast number of users would get sucked > > into > > > computations where it made no difference at all. > > > > > > Better to kill these items. > > >
