Re: Precision question

2013-01-28 Thread Zia mel
Any thoughts of this ? On Sat, Jan 26, 2013 at 10:55 AM, Zia mel ziad.kame...@gmail.com wrote: OK , in the precison when we reduce the size of sample to .1 or 0.05 , would the results be related when we check with all the data ? For example, if we have data1 and data2 and test them using 0.1

Re: Precision question

2013-01-28 Thread Sean Owen
Impossible to say. More data means a more reliable estimate all else equal. That's about it. On Jan 28, 2013 5:17 PM, Zia mel ziad.kame...@gmail.com wrote: Any thoughts of this ? On Sat, Jan 26, 2013 at 10:55 AM, Zia mel ziad.kame...@gmail.com wrote: OK , in the precison when we reduce the

Re: Precision question

2013-01-28 Thread Zia mel
What about running several tests on small data , can't that give an indicator of how big data will perform ? Thanks On Mon, Jan 28, 2013 at 11:19 AM, Sean Owen sro...@gmail.com wrote: Impossible to say. More data means a more reliable estimate all else equal. That's about it. On Jan 28, 2013

Re: Precision question

2013-01-28 Thread Sean Owen
Yes several independent samples of all the data will, together, give you a better estimate of the real metric value than any individual one. On Mon, Jan 28, 2013 at 5:41 PM, Zia mel ziad.kame...@gmail.com wrote: What about running several tests on small data , can't that give an indicator of

Re: Precision question

2013-01-25 Thread Sean Owen
The way I do it is to set x different for each user, to the number of items in the user's test set -- you ask for x recommendations. This makes precision == recall, note. It dodges this problem though. Otherwise, if you fix x, the condition you need is stronger, really: each user needs = x *test

Re: Precision question

2013-01-25 Thread Zia mel
Interesting. Using IRStatistics stats = evaluator.evaluate(recommenderBuilder, null, model, null, 5, GenericRecommenderIRStatsEvaluator.CHOOSE_THRESHOLD, 1.0); Can it be adjusted to each user ? In other

Re: Precision question

2013-01-25 Thread Sean Owen
No, it takes a fixed at value. You can modify it to do whatever you want. You will see it doesn't bother with users with little data, like 2*at data points. On Fri, Jan 25, 2013 at 6:23 PM, Zia mel ziad.kame...@gmail.com wrote: Interesting. Using IRStatistics stats =