Moses-support Digest, Vol 103, Issue 60

Send Moses-support mailing list submissions to
moses-support@mit.edu

To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.mit.edu/mailman/listinfo/moses-support
or, via email, send a message with subject or body 'help' to
moses-support-request@mit.edu

You can reach the person managing the list at
moses-support-owner@mit.edu

When replying, please edit your Subject line so it is more specific
than "Re: Contents of Moses-support digest..."


Today's Topics:

1. Re: keep some features fixed when tuning (Vito Mandorino)


----------------------------------------------------------------------

Message: 1
Date: Sat, 23 May 2015 11:39:32 +0200
From: Vito Mandorino <vito.mandorino@linguacustodia.com>
Subject: Re: [Moses-support] keep some features fixed when tuning
To: Rico Sennrich <rico.sennrich@gmx.ch>
Cc: moses-support <moses-support@mit.edu>
Message-ID:
<CA+8mSmHN8pU-6_6Md_TzZTe2Qj47r4TxTHDC6bF_m-tE1-uy8A@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

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" <rico.sennrich@gmx.ch> 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 <rico.sennrich@gmx.ch>:
>
>> 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
>> Moses-support@mit.edu
>> 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 :* *vito.mandorino@linguacustodia.com
> <massinissa.ahmim@linguacustodia.com>*
>
> *Website :* *www.linguacustodia.com <http://www.linguacustodia.com/> -
> www.thetranslationtrustee.com <http://www.thetranslationtrustee.com/>*
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.mit.edu/mailman/private/moses-support/attachments/20150523/39bcbfa7/attachment-0001.htm
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 4421 bytes
Desc: not available
Url : http://mailman.mit.edu/mailman/private/moses-support/attachments/20150523/39bcbfa7/attachment-0001.jpg

------------------------------

_______________________________________________
Moses-support mailing list
Moses-support@mit.edu
http://mailman.mit.edu/mailman/listinfo/moses-support


End of Moses-support Digest, Vol 103, Issue 60
**********************************************

Tweet