If it's true that IDRescorer works on original items then that's both bad and good news for me.
The bad news is is that all the code I had previous written involving IDRescorer is all bugy since I had assumed that IDRescorer filters recommendations and not original list The bit of good news is that I don't have to anything for the new task. But, if IDRescorer changes original list, what can be used to change recommendations? On Wed, May 9, 2012 11:14 am, Sean Owen wrote: > Trust me, I'm telling you how it works since I wrote it. What is unclear > about the steps I listed below? > > Filtering happens before even *scoring*. It works exactly how you want it > to. If you're still confused please just read the source code. > > On Wed, May 9, 2012 at 9:08 AM, Mugoma Joseph Okomba > <[email protected]>wrote: > >> >> From javadoc >> ( >> https://builds.apache.org/job/Mahout-Quality/javadoc/org/apache/mahout/cf/taste/impl/recommender/GenericUserBasedRecommender.html#recommend(long,%20int,%20org.apache.mahout.cf.taste.recommender.IDRescorer) >> >> rescorer - rescoring function to apply before final list of >> recommendations is determined >> >> My take is that IDRescorer is used to determine the final list of >> recommendations (via filtering or re-scoring) but doesn't apply on the >> original items. >> >> To be clear let me give small demonstration: >> 1. Item 1 => rating 3 >> 2. Item 2 => rating 2 >> 3. Item 3 => rating 1 >> 4. Item 4 => rating 3 >> 5. Item 5 => rating 2 >> 6. Item 6 => rating 4 >> 7. Item 7 => rating 2 >> 8. Item 8 => rating 3 >> 9. Item 9 => rating 4 >> 10. Item 10 => rating 4 >> >> Original items => 10 >> >> What IDRescorer does is compute recommendations then exclude items 6,9 & >> 10 from final list via filtering. >> >> What I need is that, before recommendations are computed, only items >> 1,2,3,4,5,7,8 are considered i.e. original items should be reduced from >> 10 >> to 7 and only the 7 items should be considered by the recommender. >> >> >
