Thank you very much Rico, I'll give a try to the other options that you mention. On May 22, 2015 6:31 PM, "Rico Sennrich" <[email protected]> wrote:
> Hi Vito > > Yes, that's basically what happens, and you're right that "tuneable=false" > can be harmful to MERT - hence my warning. I've heard of people trying to > keep the weights of a language model fixed through it, and this didn't work > at all. > > MERT (but not MIRA) also supports the option "-o" to define which features > to optimize, and mert-moses.perl accepts the option "--activate-features" > to do the same (it then passes the list of features to MERT). This may be > more suitable for some cases. > > Code contributions for a better way of having fixed weights (that also > works for PRO and MIRA) are welcome. > > best wishes, > Rico > > On 22.05.2015 17:07, Vito Mandorino wrote: > > Thank you all. Can you explain further what does it mean that MERT won't > know that the feature exists? Does that mean that the tuneable feature > weights are optimized assuming that all non-tuneable feature weights are > equal to zero? > In fact, in my understanding this should lead to a dramatic decrease of > the score Bleu on the tuning set, but this is not what I ended up with in > my tests, at least in some cases (decrease of just 0.19 Bleu when adding > tuneable=false to PhrasePenalty and Distortion on a tuning set constituted > by 574 segments). > > Vito M. > > 2015-05-20 14:38 GMT+02:00 Rico Sennrich <[email protected]>: > >> Matthias Huck <mhuck@...> <mhuck@...> writes: >> >> > >> > Hi Vito, >> > >> > tuneable=false should work. >> >> Just my usual caveat: >> >> if you use 'tuneable=false', the feature score(s) won't be >> reported to the n-best list, and MERT/MIRA/PRO won't even know that the >> feature exists. This is appropriate in some cases (keeping a feature >> weight >> at 0, or giving a high penalty to some glue rules to ensure that they are >> only used if no translation is possible without them), but in other cases, >> hiding important features causes the optimizer to search the wrong space. >> >> best wishes, >> Rico >> >> _______________________________________________ >> Moses-support mailing list >> [email protected] >> http://mailman.mit.edu/mailman/listinfo/moses-support >> > > > > -- > *M**. Vito MANDORINO -- Chief Scientist* > > > [image: Description : Description : lingua_custodia_final full logo] > > *The Translation Trustee* > > *1, Place Charles de Gaulle, **78180 Montigny-le-Bretonneux* > > *Tel : +33 1 30 44 04 23 Mobile : +33 6 84 65 68 89 > <%2B33%206%2084%2065%2068%2089>* > > *Email :* *[email protected] > <[email protected]>* > > *Website :* *www.linguacustodia.com <http://www.linguacustodia.com/> - > www.thetranslationtrustee.com <http://www.thetranslationtrustee.com/>* > > >
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