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From Jamey Wood <jamey.w...@gmail.com>
Subject Re: Treating User Demographics as (Pseudo) Items?
Date Thu, 21 Jul 2011 04:22:34 GMT
Great.  Thanks, Ted!

--Jamey

On Wed, Jul 20, 2011 at 9:57 PM, Ted Dunning <ted.dunning@gmail.com> wrote:

> Oh... you do have to be careful with this a bit because some of these side
> factors can have disastrously non-sparse characteristics.  For instance, a
> large fraction of the people in the world are in each age range.  Likewise,
> there are entirely too many romance novels in the world.  These issues of
> prevalence can seriously impact your algorithm run-time (adversely).  You
> can compensate for this by sampling or just recognizing that such pervasive
> features inherently cannot be very useful since too many things would be
> recommended.
>
> On Wed, Jul 20, 2011 at 8:51 PM, Ted Dunning <ted.dunning@gmail.com>
> wrote:
>
> > Yes.  This can work.  And it can go both ways since you might do
> something
> > like combine recommendations for a specific book with more general
> > recommendations for a specific author or genre.  You can also have
> > recommendations for, say, an author or genre based on demographic
> quantities
> > such as geo-location or age range.
> >
> > It can be a bit tricky to combine all of these features.  One principled
> > way would be to extend the log-linear latent factor approach to include
> > these multiple cross terms.  A less principled, but pretty effective
> method
> > is to score all kinds of recommendations independently and then
> recalibrate
> > based on percentiles (if you can make sense of that, often not possible)
> or
> > by some declining function of rank.
> >
> >
> > On Wed, Jul 20, 2011 at 7:18 PM, Jamey Wood <jamey.wood@gmail.com>
> wrote:
> >
> >> Is there any precedent for treating users' demographic characteristics
> as
> >> items (particularly for item-based recommendation)?  For example, if one
> >> were performing item-based recommendation within a bookselling site,
> it'd
> >> be
> >> natural to include the user:item purchases as boolean preferences.  But
> >> could it also make sense to include certain user:demographic pairs as
> >> boolean preferences (e.g. user123:age40-to-50)?  Of course, these items
> >> would need to be filtered (by a Rescorer) in the recommendation outputs,
> >> but
> >> I'm curious whether including them as inputs is potentially helpful.
> >>
> >> Thanks,
> >> Jamey
> >>
> >
> >
>

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