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Multilayer proposal, not standoff revision (Re: issue-68 from an annotation representation point of view, with potential implications for annotatorsRef and standoff markup)

From: Felix Sasaki <fsasaki@w3.org>
Date: Mon, 28 Jan 2013 08:35:24 +0100
Message-ID: <51062A3C.2090806@w3.org>
To: Dave Lewis <dave.lewis@cs.tcd.ie>
CC: public-multilingualweb-lt@w3.org
Hi Dave, all,

Am 28.01.13 01:23, schrieb Dave Lewis:
> Hi Felix,
> Some thoughts on this proposal, primarily in comparison to the 
> existing stand-off mechanisms:
>
> 1) If I'm understanding this right, you seem to invert the reference 
> mechanism between the element being annotated and the local stand-off 
> element when compared to the similar mechanisms we already have for 
> locQualityIssue and provenance. i.e. the standoff element here 
> references the annotated element rather than the other way around in 
> the current standoff mechanisms.
>
> Could you clarify why this different approach is needed?

First part of the answer is: two resolve a last call comment. We can't 
easily be moving forward without doing that.
Second part of the answer: to have a broad consensus that ITS2 is a good 
thing. This is not an aspect of the w3c process. But if people think 
from the start that ITS2 is borken, we have a problem.
Third part: see my response to Yves about the "similar mechanisms" 
topic. I don't think we need to change other parts of the spec to 
accomodate issue-68. Christian, can you correct me if I'm wrong?

>
> As it stands I see the following problems with this inverted approach:
> i) it means implementors potentially need to support two mechanisms 
> for handling standoff mark-up in different data categories (and 
> therefore introduces a lot of uncertainties  for the LC compared to 
> reusing the existing mechanism)

No, see above.

> ii) this would get complex if other (non-ITS) functions are 
> creating/rewriting, the id values

No, if we restrict this to where it has a real added value (see answers 
1-3 above): disambig+terminology.

> iii) you loose the ability to associate standoff elements and content 
> through global ITS rules, and hence loose the ability to annotate 
> content in attributes.

True - but that ability is not needed for disambiguation and terminology 
anyway: as I understand it most annotation tools in both areas work on 
text content. Also, I don't have seen global rules for terminology 
working on attribute content. Others, have you?

> iv) assuming the confidence attribute stays optional (or the 
> confidence applies to several occurances), for compactness you may 
> want to refer to several elements where the annotated text reoccurs 
> from the same textAnalyticsAnnotation - this approach doesn't allow 
> that I think

Good point - you would need to allow confidence at the 
"textAnalyticsAnnotations" element as well to accomodate that, see below:

<its:textAnalyticsAnnotations annotatorsRef="tan|tool-x" 
its-tan-confidence="0.7">
<its:textAnalyticsAnnotation *ref="a8"* its-tan-type="entity" 
its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
its-tan-class-ref="http://nerd.eurecom.fr/ontology#Place" />
</its:textAnalyticsAnnotations>

Of course if "its-tan-confidence" appears at both a 
"textAnalyticsAnnotation" element and a "textAnalyticsAnnotations" 
element, the former apperance has precedence.


>
> On the other hand we still don't have a clear idea of how to apply 
> annotatorsRef for multiple annotations with the current standoff 
> pattern from lqi and provenance

Sorry, I may have missed that: could you point me to the issue number 
for that problem?

> , and we can't duck that here because its needed when confidence 
> scores are used. One approach could be to apply annotatorsRef only to 
> mtConfidence score, and use a dedicate tan-annotator attribute here.
>
> 2) a more minor issue, in your processing expectation for adding the 
> annotation, you state that if there isn't an inline attribute then you 
> should add it inline before adding a new textAnalyticsAnnotation. 
> However  with the current stand-off approaches we don't mandate this. 
> You could in fact put _all_ your annotations in the stand-off, and for 
> the XLIFF mapping for lqi and provenance we need to keep that option 
> available to implementors.

See above - I wouldn't change anything with regards to the current 
stand-off approach.

>
> 3) one general, more philosophical point. You correctly note we didn't 
> explicitly discuss whether ITS annotation mechanisms were suitable for 
> term and disambig. We've implicitly limited ourselves to data 
> categories that make sense with the existing annotation mechanisms. 
> We've stretched this a bit with local standoff and annotatorRef 
> individually, but combining these new mechanisms is not something 
> we've figured our how to do yet (a symptom of that stretching).

Again, can you point me to the open issues? See the question above. I 
had thought we had resolved these at the f2f (even if not with perfect 
solutions), but if there is something to follow up on I'm eager to see 
it rather soon.

> The approach you suggest here seems to add a new type of annotation 
> pattern, stretching us further.

Only if we try to make it a general principle. Otherwise I think it is a 
pretty easy implementation appraoch (see the "resolve all ID attributes" 
in the reply to Yves' mail).

>
> Perhaps its better to restrict ourselves to what makes sense to do 
> with existing, tested ITS mechanism while adding pointers to external 
> formats that can be used for the more complicated cases that these 
> can't handle. We took this approach with provenance, where we support 
> simple agent provenance inline and provide an external link which 
> gives us the possibility to build best practice for combining ITS and 
> the W3C PROV model for more complex cases (see ISSUE-71).


Good point - however, this would leave us open with issue-68, see my 
answers 1-3 above.


>
> So we could allow a link to NIF to deal with cases where we have 
> multiple annotations for the same text, or nested annotations or 
> overlapping annotations, which NIF is designed to deal with.

NIF too has open issues, and we have a weak implementation committment 
for it: just two, Sebastian and I, and Sebastian obviously is busy with 
other stuff too. So I'm not 100% sure whether we can count on NIF here.
Besides, see the comment from Yves on this: NIF is yet another 
implementation branch. The mutilayer proposal (using now a different 
terminology, and a different mail subject) is ideally just one 
additional method while traversing the document tree: 
getTanAnnotations(nodeID), with nodeID being the xml:id or ID attribute.

> With some sensible best practice, we could use a combination of 
> termInfoRef and NIF to deal with many of these more complex cases.

See again Yves' reply. As a prototype implementer, I think that the 
multilayer approach is easy to do.
Also, note that it relies on element nodes and their IDs, and not on 
character offsets. The ID attributes have of course stability issues, 
but with character offsets these are even worse - a pure re-formatting 
destroys the offsets. See again the NIF issue.

>
> Essentially I'm arguing for the status quo here, living with limited 
> but still useful  scope of current term+disambig inline and using best 
> practice to give us the time to work out upgrade paths from this to 
> supporting more complex use cases with term+disambig+NIF.

Thanks a lot for the feedback - I understand your position I think, but 
I hope that we can continue the discussion on this, to avoid a monster 
data category or to avoid concerns on ITS2 from the start.


Best,

Felix

>
> cheers,
> Dave
>
> On 27/01/2013 07:24, Felix Sasaki wrote:
>> Hi all,
>>
>> sorry, this is going to be long ... but please have a look, esp. the 
>> implementers (both consumers and producers) of terminology and 
>> disambiguation.
>>
>> in the last 10 1/2 months, since Tadej's presentation at the Dublin 
>> workshop, we had a lot of discussions on disambiguation, and 
>> sometimes (as now) including terminology. But it seems that we never 
>> discussed whether ITS2 approach of selection (global, local, 
>> inheritence, overriding (partial or not)...) is suitable for this 
>> type of information.
>>
>> By "this type" I mean annotation of linguistic information. Most ITS2 
>> and ITS1 data categories are process related (e.g. "Don't translate 
>> this ..."), but both terminology and what's now called disambiguation 
>> are information that you find in linguistic corpora and processing 
>> tools. Now, my point is that in both in such natural language 
>> processing tool chains and related corpora, a representation of 
>> information *inline per document node* is rather the exception. 
>> Mostly you have *standoff information*, that is a complete seperation 
>> of information from actual content - as in NIF.
>>
>> Why is that? In linguistic annotation it is common that you have 
>> several layers of information, like our lexical, ontological etc. 
>> information. Some of these might be complex in itself (e.g. named 
>> entities), some of these might be related to others (e.g. an 
>> ontological concept related to a lexical item). I won't try to define 
>> these layers here - but my point is that due to the complexity of 
>> representing such information inline, nearly nobody is trying to 
>> represent several layers at the same time inline. The common approach 
>> is rather to have a base layer, and then pointers from the various 
>> annotation layers.
>>
>> In a sense you can describe NIF as an approach of taking character 
>> offsets as the implicit base layer (implicit because characters don't 
>> need explicit anchors). The TEI here
>> http://www.tei-c.org/release/doc/tei-p5-doc/en/html/NH.html#NHSO
>> provides an example for an offset using words as the base unit, with 
>> exlicit xml:id attributes.
>>
>> So far we haven't taken this approach for terminology or 
>> disambiguation. This is why we had to came of with 16+ attributes: if 
>> you want to do everything "inline", you need to differenciate 
>> attribute names and come up with a monster data category. Inline 
>> annotations are just not suitable for such information.
>>
>> So, the first idea behind below approach is: if you want to represent 
>> just one linguistic layer (or "qualifier" in Christian's mail at
>> http://lists.w3.org/Archives/Public/public-multilingualweb-lt-comments/2013Jan/0014.html
>> ) , you use "tan-type" attribute to differentiate annotations. That 
>> leads to following models inline models:
>>
>> 1) A term has its-tan-type with value "term" and optional 
>> its-tan-confidence, its-tan-ident-ref, and its-tan-info-ref. Example:
>> <span its-tan-type="term" 
>> its-tan-ident-ref="http://termdatabase.example.com/entry37" 
>> its-tan-info-ref="http://termdatabase.example.com/entry37/description" its-tan-confidence="1.0">Dublin</span>
>> Comparison to current ITS1 "Terminology":
>> its-tan-type="term" plays the role of term="yes". its-tan-info-ref 
>> plays the role of termInfoRef. its-tan-ident-ref links to a term data 
>> base. its-tan-confidence provide confidence information.
>> (Esp. at Marcis: I know that "Dublin" is a bad candidate for a term, 
>> I'm just trying to exemplify the annotation approach here)
>>
>> 2) An entity has its-tan-type with value "entity" and optional 
>> its-tan-confidence, its-tan-ident-ref, and its-tan-class-ref. Example:
>> <span its-tan-type="entity" 
>> its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
>> its-tan-class-ref=" http://nerd.eurecom.fr/ontology#Place" 
>> its-tan-confidence="0.7">Dublin</span>
>>
>> So above is only different naming compared to current "Terminology" 
>> and Disambiguation. Below is now the standoff approach. The 
>> processing expectation for tools *producing the annotation* is like this:
>> - If there is no inline annotation, just create it (e.g. 1) or 2))
>> - If there is inline annotation, check if there is an id attribute 
>> (in HTML) or xml:id (if XML serizalization of HTML is used and with 
>> lower precedence compared to id). For formats other than HTML, add 
>> xml:id if possible or use the id attribute appropriate for that format.
>>
>> Then, for creating standoff annotations, add an 
>> "its:textAnalyticsAnnotations" element to the document, e.g. in HTML 
>> "script" if needed.
>>
>> Let's assume before annotation we have
>> <span its-tan-type="entity" 
>> its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
>> its-tan-class-ref="http://nerd.eurecom.fr/ontology#Place" 
>> its-tan-confidence="0.7">Dublin</span>
>> Then after annotation we would have
>> <span its-tan-type="entity" 
>> its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
>> its-tan-class-ref="http://nerd.eurecom.fr/ontology#Place" 
>> its-tan-confidence="0.7" *id="a8"*>Dublin</span>
>> and this:
>> <its:textAnalyticsAnnotations>
>> <its:textAnalyticsAnnotation *ref="a8"* its-tan-type="term" 
>> its-tan-ident-ref="http://termdatabase.example.com/entry37" 
>> its-tan-info-ref="http://termdatabase.example.com/entry37/description" its-tan-confidence="1.0"/>
>> </its:textAnalyticsAnnotations>
>>
>> Let's now assume that before annotation we have
>> <span its-tan-type="term" 
>> its-tan-ident-ref="http://termdatabase.example.com/entry37" 
>> its-tan-info-ref="http://termdatabase.example.com/entry37/description" its-tan-confidence="1.0">Dublin</span>
>> Then after annotation we would have
>> <span its-tan-type="term" 
>> its-tan-ident-ref="http://termdatabase.example.com/entry37" 
>> its-tan-info-ref="http://termdatabase.example.com/entry37/description" its-tan-confidence="1.0" 
>> *id="a8"*>Dublin</span>
>> and this:
>> <its:textAnalyticsAnnotations annotatorsRef="tan|tool-x">
>> <its:textAnalyticsAnnotation *ref="a8"* its-tan-type="entity" 
>> its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
>> its-tan-class-ref="http://nerd.eurecom.fr/ontology#Place" 
>> its-tan-confidence="0.7"/>
>> </its:textAnalyticsAnnotations>
>>
>> Now, if several "entity" annotation tools have been used, we could 
>> also have
>> <its:textAnalyticsAnnotations>
>> <its:textAnalyticsAnnotation *ref="a8"* its-tan-type="entity" 
>> its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
>> its-tan-class-ref="http://nerd.eurecom.fr/ontology#Place" 
>> its-tan-confidence="0.7" annotatorsRef="tan|tool-x"/>
>> <its:textAnalyticsAnnotation *ref="a8"* its-tan-type="entity" 
>> its-tan-ident-ref="http://dbpedia.org/resource/Dublin" 
>> its-tan-class-ref="http://nerd.eurecom.fr/ontology#Place" 
>> its-tan-confidence="0.4" annotatorsRef="tan|tool-y"/>
>> </its:textAnalyticsAnnotations>
>>
>> Above approach would also influence the consumption of this data 
>> category, and of annotatorsRef:
>>
>> - A consuming tools goes through the document and gathers all 
>> textAnalyticsAnnotations elements
>> - It then goes through the document. For each element node
>> * check for existing inline markup. If it's available, add it to the 
>> list of annotations for that node. Assume the inline version up in 
>> the document tree of annotatorsRef to be responsible for the 
>> annotation of that markup.
>> * check the accumulated standoff textAnalyticsAnnotations elements 
>> for occurrences of IDs that match the node. If there is such an ID, 
>> add the related annotation to the list for the node, including the 
>> additional annotatorsRef tool, e.g. tool-x or tool-y in the above case.
>>
>>
>> In summary, this standoff tries to solve several issues:
>>
>> - avoid the 16+ inline attribute monster data category
>> - allow for multiple annotations of the same span, with different tools
>> - avoid the ITS1/2 or general inline annotation issues with 
>> inheritance and overriding - as with the standoff approach at 
>> exemplified at
>> http://www.tei-c.org/release/doc/tei-p5-doc/en/html/NH.html#NHSO
>> annotation information is just accumulated for a given base item (in 
>> our case, element nodes with an ID).
>>
>> I'm not yet asking for this change, but I see it as a way forward 
>> that could make the life of both annotation producers (Marcis and 
>> Tadej) and consumers (Yves et al.) simpler. So I'm eager to hear 
>> thoughts on this :)
>>
>> Thoughts?
>>
>> - Felix
>
Received on Monday, 28 January 2013 07:39:41 UTC

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