Just whistling in the wind here ... Perhaps before any changes are made to universally toggle cTakes in one direction or the other, we can take a poll of when & where cTakes/Ytex/OpenNLP/Omaha needs a Sentence (ignoring CR/LF) as opposed to a Line (CR/LF delimited PLUS -sentence-)
If some capabilities like negation detection require -lines- then would it make more sense to have Sentence ignore -newline- and negation detection itself split the Sentence into line items? If an annotator is interested in list items, each of which may be on a distinct -line-, then it can split up the Sentence as needed. I think that James hints that cTakes code already does this in some places. If a good deal of functionality requires -newline- delimited types, would it make sense to introduce a type Line? If something uses a structured list it could iterate through Line types, while something using pure text could iterate through Sentence types. This facilitates section-by-section different behavior, does not require any decision on global defaults, and makes data selection for training Sentence a nonesuch wrt line breaks. However, it adds to the system and would require a per-use choice decision by developers OR a toggle by users (back to the default decision). Perhaps this has already been tried? Sean -----Original Message----- From: Masanz, James J. [mailto:masanz.ja...@mayo.edu] Sent: Wednesday, January 22, 2014 1:06 PM To: 'dev@ctakes.apache.org' Subject: RE: sentence detector newline behavior The only rule I know of is that cTAKES (prior to ytex integration) always forces a sentence break at a newline. This was because the clinical notes cTAKES original processed never had newlines in the middle of a sentence, but did need sentence breaks to occur at end of sentence for good negation detection on those notes. I think Guergana earlier mentioned other EMRs also have this need, but it seems to not be ubiquitous. >From others' posts, it seems that we could use an option in cTAKES to turn off >this forcing of sentence breaks at newlines (or depending on how you look at >it, an option to turn on the forcing of sentence breaks if we change the >default behavior) I think we (cTAKES) need to decide the following: - do we want to do this for entire notes, or would it be worth it to have it be on a section-by-section basis. - what do we make the default behavior - to force or not to force newlines to be sentence breaks - what data (that contains newlines) will we use for training the sentence detector Regardless of those answers, I think OpenNLP support for including newlines in training data would be valuable for those others who have sentences that span lines. And having an option on OpenNLP to always break at newline would be useful for at least some cTAKES users (and we could remove the cTAKES code that does that) -- James -----Original Message----- From: dev-return-2390-Masanz.James=mayo....@ctakes.apache.org [mailto:dev-return-2390-Masanz.James=mayo....@ctakes.apache.org] On Behalf Of Jörn Kottmann Sent: Tuesday, January 21, 2014 4:29 AM To: dev@ctakes.apache.org Subject: Re: sentence detector newline behavior Yes, exactly, OPENNLP-602 is about training a sentence detector model which can use a new line as a end-of-sentence character. In case you have certain rules to split sentences we should have a look at them. The Sentence Detector could be extended to support a user provided rule based splitter. If there is an interest in that we could probably get it into 1.6.0 as well. Jörn On 01/20/2014 10:02 PM, Chen, Pei wrote: > I presume Joern was suggesting that if he supports new lines in the opennlp > SentenceDectector (either part of the trained models or post processing with > some rules?) cTAKES will be able to use it out of the box and we should be > able remove any additional custom logic that we currently have- which seems > like a good idea. > > [but when to use within cTAKES individual components such as negation > might be another discussion?] --Pei > >> On Jan 20, 2014, at 12:46 PM, "vijay garla" <vnga...@gmail.com> wrote: >> >> The sentence detection opennlp model used by ctakes does not split >> sentences at newlines - there is additional logic in the takes >> sentence splitter that does this (and an alternative impl that >> doesn't is in the ytex branch). Afaik no retraining / change to the >> feature representation is necessary. >> >> Vj >> >>> On Monday, January 20, 2014, Jörn Kottmann <kottm...@gmail.com> wrote: >>> >>> Hi all, >>> >>> currently I have quite a bit of time to work on OpenNLP, and would >>> like to help you out with this issue. >>> >>> Here is the follow up issue for this change: >>> https://issues.apache.org/jira/browse/OPENNLP-602 >>> >>> I am still trying to figure out what would be the best option to >>> implement this. >>> In the training data a user could just use a special tag to identify >>> the chars. >>> >>> Instead of <NEWLINE> it might be better to use <CR> and <LF> to >>> encode these two chars in the training data. Any thoughts? >>> >>> I am planning to release this as part of OpenNLP 1.6.0. >>> >>> Thanks, >>> Jörn >>> >>>> On 05/22/2013 02:03 PM, Jörn Kottmann wrote: >>>> >>>>> On 05/22/2013 01:17 PM, Miller, Timothy wrote: >>>>> >>>>> That's awesome! It might be worth trying at least. How does the >>>>> training process change? Previously the training data would be one >>>>> sentence per line, but with newlines as possible mid-sentence >>>>> characters that could be trouble, is there a new representation >>>>> for training data? Or would we have to use the training api? >>>> Good point, yes that will be a problem with the default training >>>> format, but it shouldn't be hard to solve. In the format itself we >>>> could define a new line tag e.g. >>>> <NEWLINE> to mark new lines. >>>> as a hack to make it work with 1.5.3 you could instead use a >>>> special char as a replacement for the new line char. >>>> When you pass the text down to the sentence detector a simple >>>> string replace could be used to convert all new line chars to the >>>> special new line marker char. >>>> >>>> If things work out for you performance wise as well we will just >>>> integrate it properly into OpenNLP for the next release. >>>> >>>> Could you produce a sentence detector training file with a new line >>>> marker char? >>>> >>>> You should try to pick a char you can also pass in on a terminal >>>> otherwise you have to use the API to train the model. The build in >>>> cross validation could be used to evaluate the performance. >>>> >>>> Jörn >>>