That is good for making a test repeatable because you are picking the same random sample repeatedly. For evaluation purposes here that's not a good thing and you do want several actually different samples of the result. On Jan 23, 2013 1:19 PM, "Stevo Slavić" <ssla...@gmail.com> wrote:
> When evaluating recommender before running evaluator put > > RandomUtils.useTestSeed(); > > to make splitting of data set consistent; don't use it in production, just > for evaluation. > This is all explained more thoroughly in Mahout in Action book. > > Kind regards, > Stevo Slavic. > > > On Wed, Jan 23, 2013 at 2:01 PM, Zia mel <ziad.kame...@gmail.com> wrote: > > > Hi > > I used NearestNUserNeighborhood with RMSE in a user recommender that > > use PearsonCorrelationSimilarity , I found that changing the > > neighborhood size has no clear pattern or effect. Sometimes it > > increase others decrease. While using the neighborhood size with > > precision has a better pattern. Any reason? Another point is that the > > RMSE change for every run since it choose different sample , so would > > running the code for 10 or 20 times and taking the average be a good > > idea or there is better thing to do? > > > > //-- RUN 1 > > 2, 0.5523623146152608 > > 3, 0.5425283201773704 > > 4, 0.669846658662311 > > 5, 0.5956616542334392 > > 6, 0.6033911039809353 > > 7, 0.6135206544496685 > > 8, 0.5740444208649034 > > 9, 0.642798288443049 > > 10, 0.6266535555651472 > > > > //-- RUN 2 > > 2, 0.5415411343523825 > > 3, 0.6784589323396696 > > 4, 0.6347069968141124 > > 5, 0.6968820296725008 > > 6, 0.5953849874479478 > > 7, 0.6791828191904128 > > 8, 0.6072462830257853 > > 9, 0.6461346217476011 > > 10, 0.6043919119341171 > > > > Thanks ! > > >
