Hello Rico,
Now that you mention it I also performed an additional test.
I took a translation and obtained the perplexity score by querying the
kenlm and nplm from the command line. In this case the difference between
the scores was not that large.
It might be an encoding issue.
I will check again and let you know.

However the data I am using to train the LM's (KENLM, NPLM and BILM) is
the  same as I am using to train. I should also mention that I did no
tokenization etc before training the LM's and the TM.
Thanks for your replies.
Regards.

On Tue, Jul 7, 2015 at 1:18 AM, Rico Sennrich <[email protected]> wrote:

>  Hi Raj,
>
> the information you provide is pretty vague, so I'm just making some wild
> guesses here:
>
> it could be a user error, for instance an inconsistency between the
> training sets used for training BilingualNPLM and the phrase table. Check
> that the same version of the corpus (including tokenization, truecasing
> etc.) was used for training, and that you did not mix up source and target
> language. Also check that the settings during training are consistent with
> those in the moses.ini file.
>
> it's possible that some of the settings (vocabulary size, number of
> training epochs, or similar) are unsuitable for your task. For example,
> since you have a relatively small training corpus, you may need more epochs
> of training to get good results (use a validation set to see if model
> perplexity converges).
>
> please double-check that there were no problems with the unicode-handling
> of Japanese/Chinese characters, and that the encoding of your vocabulary
> files matches that of the translation model, and the decoder input. We have
> never experienced such problems, but they could arise for some system
> configurations.
>
> best wishes,
> Rico
>
>
>
> On 06.07.2015 16:31, Raj Dabre wrote:
>
>    Hello Rico,
>  I trained both mono as well as bilingual LM's.
>  Both seemed ineffective.
>  As I mentioned before, I am working with Chinese-Japanese and the domain
> is paper abstracts.
>  I did check the n-best lists and I saw a significant difference between
> the LM scores when comparing the runs for KenLm and NPLM.
>  What could have gone wrong during the training?
>  Regards.
>
> On Mon, Jul 6, 2015 at 10:53 PM, Rico Sennrich <[email protected]>
> wrote:
>
>>  Hello Raj,
>>
>> can you please clarify if you tried to train a monolingual LM (NeuralLM),
>> a bilingual LM (BilingualNPLM), or both? Our previous experiences with
>> BilingualNPLM are mixed, and we observed improvements for some tasks and
>> language pairs, but not for others. See for instance:
>>
>> Alexandra Birch, Matthias Huck, Nadir Durrani, Nikolay Bogoychev and
>> Philipp Koehn. 2014. Edinburgh SLT and MT System Description for the IWSLT
>> 2014 Evaluation. Proceedings of IWSLT 2014.
>>
>> To help debugging, you can check the scores in the n-best lists of the
>> tuning runs. If the NPLM features give much higher costs than KenLM
>> (trained on the same data), this can indicate that something went wrong
>> during training.
>>
>> best wishes,
>> Rico
>>
>> On 06.07.2015 14:29, Raj Dabre wrote:
>>
>>      Dear all,
>>  I have checked out the latest version of moses and nplm and compiled
>> moses successfully with the --with-nplm option.
>>  I got a ton of warnings during compilation but in the end it all worked
>> out and all the desired binaries were created. Simply executing the moses
>> binary told me the the BilingualNPLM and NeuralLM features were available.
>>
>>  I trained an NPLM model based on the instructions here:
>> http://www.statmt.org/moses/?n=FactoredTraining.BuildingLanguageModel#ntoc33
>>  The corpus size I used was about 600k lines (for Chinese-Japanese;
>> Target is Japanese)
>>
>>  I then integrated the resultant language model (after 10 iterations)
>> into the decoding process by moses.ini
>>
>>  I initiated tuning (standard parameters) and I got no errors, which
>> means that the neural language model (NPLM) was recognized and queried
>> appropriately.
>>  I also ran tuning without a language model.
>>
>>  The strange thing is that the tuning and test BLEU scores for both
>> these cases are almost the same. I checked the weights and saw that the LM
>> was assigned a very low weight.
>>
>>  On the other hand when I used KENLM on the same data.... I had
>> comparatively higher BLEU scores.
>>
>>  Am I missing something? Am I using the NeuralLM in an incorrect way?
>>
>>  Thanks in advance.
>>
>>
>>
>> --
>>   Raj Dabre.
>> Doctoral Student,
>>  Graduate School of Informatics,
>> Kyoto University.
>>  CSE MTech, IITB., 2011-2014
>>
>>
>>
>>  _______________________________________________
>> Moses-support mailing 
>> [email protected]http://mailman.mit.edu/mailman/listinfo/moses-support
>>
>>
>>
>> _______________________________________________
>> Moses-support mailing list
>> [email protected]
>> http://mailman.mit.edu/mailman/listinfo/moses-support
>>
>>
>
>
> --
>   Raj Dabre.
> Doctoral Student,
>  Graduate School of Informatics,
> Kyoto University.
>  CSE MTech, IITB., 2011-2014
>
>
>
> _______________________________________________
> Moses-support mailing list
> [email protected]
> http://mailman.mit.edu/mailman/listinfo/moses-support
>
>


-- 
Raj Dabre.
Doctoral Student,
Graduate School of Informatics,
Kyoto University.
CSE MTech, IITB., 2011-2014
_______________________________________________
Moses-support mailing list
[email protected]
http://mailman.mit.edu/mailman/listinfo/moses-support

Reply via email to