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From Em <mailformailingli...@yahoo.de>
Subject Re: Exclude by RuleSet
Date Mon, 04 Jul 2011 10:56:32 GMT
Hi Marco,

thank you for pointing me to this direction.

Again I have to ask: What would be more efficient? Rescoring or
CandidateItemStrategy? Where are the differences?

Thanks!


Am 04.07.2011 12:39, schrieb Marko Ciric:
> 
> Hi Em,
> 
> If I understood well what you're asking, you could implement a new
> CandidateItemStrategy class. If you see that interface, there's this
> method getCandidateItems(long userID, DataModel dataModel) that has all
> parameters you need in order to filter out items that belong to the
> unwanted category.
> This class is actually used inside an item-based recommender.
> 
> On 07/02/2011 03:53 PM, Em wrote:
>> Hi Steven,
>>
>> That would be the alternative. Create different data-models per
>> category, yes.
>>
>> Does this affect the quality of your recommendations in comparison to a
>> data-model that contains also not-relevant data for the current
>> category/situation/social-graph but the unwanted recommendations are
>> filtered out by a Rescorer?
>>
>> Regards,
>> Em
>>
>> Am 02.07.2011 15:22, schrieb Steven Bourke:
>>> Assuming you have the technical resources, one approach could involve
>>> just
>>> containing different 'conditions' into different data models.
>>>
>>> For instance I have one setup that only has users from someones social
>>> graph, and another that includes all my users. When generating
>>> recommendations I just point it to whichever datasource is required.
>>>
>>>
>>> On Fri, Jul 1, 2011 at 7:25 PM, Sean Owen<srowen@gmail.com>  wrote:
>>>
>>>>  From what you describe so far, you do not need any new code. A
>>>> Rescorer does what you want, I believe. If not, maybe you can explain
>>>> more about what it's not doing that you want it to do. A Rescorer to
>>>> exclude items is probably always a good idea as it saves computation.
>>>>
>>>> On Fri, Jul 1, 2011 at 7:03 PM, Em<mailformailinglists@yahoo.de> 
>>>> wrote:
>>>>> Hi Sean,
>>>>>
>>>>> I am not very familiar with the code itself, however I have no problem
>>>>> with digging into it.
>>>>>
>>>>> I guess the CandidateItemStrategy and the Rescorer are usable for all
>>>>> kinds of recommendations: user-user, user-item, item-item etc. and
>>>>> so I
>>>>> can create a generic (or general) implementation for the problem?
>>>>>
>>>>> Could you explain more of the tradeoffs for both
>>>>> implementation-possibilities, please?
>>>>>
>>>>> Regards,
>>>>> Em
>>>>>
>>>>> Am 01.07.2011 19:01, schrieb Sean Owen:
>>>>>> The short answer is that you'd have to modify the code to inject
this
>>>>>> kind of logic -- though you might get away with just using a custom
>>>>>> CandidateItemStrategy in an item-based recommender.
>>>>>>
>>>>>> A Rescorer will cause it to not bother computing estimated values
for
>>>>>> unwanted items though, so I think it already does what you intend.
>>>>>>
>>>>>> On Fri, Jul 1, 2011 at 5:56 PM, Em<mailformailinglists@yahoo.de>
>>>> wrote:
>>>>>>> Hello list,
>>>>>>>
>>>>>>> is it possible to filter out some items/users from the
>>>>>>> recommendation-process?
>>>>>>>
>>>>>>> In some cases one does not want to include information from some
>>>> sources in
>>>>>>> special situations.
>>>>>>>
>>>>>>> As an example you can imagine an onlineshop. If you click on
the
>>>> category
>>>>>>> "women" it would be the best to only show recommendations for
this
>>>>>>> main-category rather than also showing some stuff for men.
>>>>>>>
>>>>>>> A Rescorer could be a solution to filter out those unwanted results
>>>> *after*
>>>>>>> the big part is done (am I correct?), however I do not want to
spend
>>>>>>> ressources on computing probabilities for items that are definitly
>>>> unwanted
>>>>>>> for the resultset.
>>>>>>>
>>>>>>> What I want is something like a
>>>>>>> SELECT col1, col2, col3 FROM myData WHERE category = "women"
OR
>>>> category =
>>>>>>> "subcategoryOfWomen"
>>>>>>> and than do the computation on top of this dataset.
>>>>>>>
>>>>>>> Is this possible with Mahout?
>>>>>>>
>>>>>>> Regards,
>>>>>>> Em
>>>>>>>
>>>>>>> -- 
>>>>>>> View this message in context:
>>>> http://lucene.472066.n3.nabble.com/Exclude-by-RuleSet-tp3129982p3129982.html
>>>>
>>>>>>> Sent from the Mahout User List mailing list archive at Nabble.com.
>>>>>>>
> 
> 

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