Stührenberg, Maik, and Daniel Jettka. “A toolkit for multi-dimensional markup: The development of SGF to XStandoff.” Presented at Balisage: The Markup Conference 2009, Montréal, Canada, August 11 - 14, 2009. In Proceedings of Balisage: The Markup Conference 2009. Balisage Series on Markup Technologies, vol. 3 (2009). https://doi.org/10.4242/BalisageVol3.Stuhrenberg01.
Balisage: The Markup Conference 2009 August 11 - 14, 2009
Balisage Paper: A toolkit for multi-dimensional markup
The development of SGF to XStandoff
Maik Stührenberg
Maik Stührenberg studied Computational Linguistics at Bielefeld University. He worked
four years as research assistant at Giessen University in different text-technological
projects together with Henning Lobin and Georg Rehm. He now works as a research assistant
at Bielefeld University together with Andreas Witt, Dieter Metzing and Daniela Goecke
in
the Sekimo project of the Research Group Text-technological modelling of information funded by the German
Research Foundation. His main research interests include specifications for structuring
multiple annotated data and query languages and query processing.
Daniel Jettka
Daniel Jettka works on his Master degree in linguistics after acquiring a BA in text
technology. During his studies he worked together with Andreas Witt, Dieter Metzing,
Daniela Goecke and Maik Stührenberg in the Sekimo project
of the Research Group 437 Text-technological modelling of
information funded by the German Research Foundation on different XSLT
stylesheets for the handling and transformation of overlapping markup.
In this paper we describe the extended standoff approach defined by XStandoff (the
successor of the Sekimo Generic Format, SGF), together with the accompanied collection
of
XSLT stylesheets. SGF has undergone further developments after its first presentation
(cf.
Stührenberg and Goecke, 2008) which resulted into the new development version called
XStandoff containing different changes addressed in this paper. In addition, refinements
have been made to the already available transformation scripts that help generating
SGF and
XStandoff instances and newly developed stylesheets have been added for the deletion
of
single XStandoff annotations and the conversion into inline representations.
The work presented in this paper is part of the project A2 (Sekimo) of the Research Group 437 Text-technological
modelling of information funded by the German Research Foundation[1].
Introduction
Multi-dimensionally annotated linguistic corpora have been established as a means
for
thorough linguistic analysis during the last years. An overview of architectures for
complex
or concurrent markup including non-XML based approaches such as the Layered Markup and Annotation Language (LMNL, cf. Tennison, 2002, Cowan et al., 2006) in conjunction with Trojan milestones following the HORSE
(Hierarchy-Obfuscating Really Spiffy Encoding) or CLIX
model can be found in DeRose, 2004. Sperberg-McQueen, 2007 and
Marinelli et al., 2008, too, discuss and compare state of the art approaches in
overlapping markup such as colored XML (cf. Jagadish et al., 2004) and the tabling
approach described by Durusau and O'Donnel, 2004, further approaches can be found in Stührenberg and Goecke, 2008. However, since standardization efforts with respect to a
sustainable (i.e. preferable XML-based) annotation format and mechanism (e.g. the
Graph-based Format for Linguistic Annotations, GrAF, cf. Ide and Suderman, 2007) have not yet been finished, other XML-based solutions are available,
such as using multiple or twin documents (as Marinelli et al., 2008 call them if they share some annotation, the so-called sacred markup). The Text Encoding
Initiative (TEI, Burnard and Bauman, 2008) proposes additional solutions for
dealing with multi-dimensional markup: apart from standoff markup, (cf. Thompson and McKelvie, 1997 and TEI's chapters 16.9 and 20.4), milestone elements (chapter
20.2) or fragmentations and joints (chapter 20.3) can be used. Witt et al., 2009
describe a system that adopts TEI's feature structures (chapter 18) as a meta-format
for
representing heterogenous complex markup.
While most of the before mentioned approaches target at the representation of
multi-dimensional annotation, their usage in validating and analyzing multiple annotation
layers is restricted: non-XML-based formats usually lack mechanisms for validating
overlapping
markup, since most proposed document grammar formalisms remain in a proposal state
only, such
as Rabbit/Duck grammars for GODDAG (general ordered-descendant directed acyclic graph)
structures/TexMECS (cf. Sperberg-McQueen, 2006), XCONCUR-CL (cf. Schonefeld, 2007) or Creole (Composable Regular Expressions
for Overlapping Languages etc., cf. Tennison, 2007) a powerful
extension to RELAX NG (ISO/IEC 19757-2:2003) developed in the LMNL community. The same
holds for the support for XML's companion specifications such as XPath, XSLT or XQuery
(although at least alternative query languages have been proposed by Jagadish et al., 2004, Iacob and Dekhtyar, 2005, Iacob and Dekhtyar, 2005a, Alink et al., 2006, Alink et al., 2006a and especially Bird et al., 2006 for linguistic analysis). So if validating complex markup is an issue, it is easier
to
stick with XML-based approaches, such as NITE (cf. Carletta et al., 2003, Carletta et al., 2005), PAULA (Potsdam Austauschformat für
Linguistische Annotationen, Potsdam Interchange Format for
Linguistic Annotation, cf. Dipper, 2005, Dipper et al., 2007) or the Sekimo Generic Format (SGF,
cf. Stührenberg and Goecke, 2008 and the following section).
SGF – the story so far
The development of the Sekimo Generic Format (SGF) has begun in 2006 and has been
grounded
on the Prolog fact base format that was introduced by Witt, 2002 and Witt, 2004 after first proposals by Sperberg-McQueen et al., 2000 and
Sperberg-McQueen et al., 2002. SGF was developed for storing multiple annotated
linguistic corpus data and examining relationships between elements derived from different
annotation layers in an XML conformant way. Speaking in technical terms, SGF follows
the
Annotation Graph's formal model (cf. Bird and Liberman, 1999, Bird and Liberman, 2001)
and modifies the classic standoff approach in the way that multiple annotation layers
are
stored together in a single instance while XML namespaces are used to differentiate
between
SGF's base layer, metadata and annotation layers. This allows for the application
of SGF for a
large variety of linguistic annotations, including diachronic corpora and multimodal
annotation, amongst others.
The basic principle of the Sekimo Generic Format (and its successor, XStandoff, cf.
section “The development of SGF to XStandoff”) is the use of positions in the character stream (or in time) for
referring to annotations[2].
Figure 1: Addressing character positions
T h e s u n s h i n e s b r i g h t e r .
00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24
This character stream is used to link between annotations and the primary data. A
classic
example of concurring annotations where overlaps may occur is the combination of morpheme
and
syllable annotation. We start with the morpheme annotation shown in Figure 2.
Figure 2: Morpheme annotation for a simple sentence
The graphic representation of this annotation can be seen in Figure 5.
Figure 5: Graphic representation of the syllable annotation layer
When one tries to combine both annotation levels an overlap occurs at the position
of the
't' in the word 'brighter', which can easily be observed in Figure 6.
Figure 6: Combined graphic representation of both annotation layers (labels removed for
readability reasons)
Classic XML-based inline annotation formats fail to model these overlapping structures
due
to their formal model of a single-rooted tree while classic standoff annotation (i.e.
using
markup separated from the primary data and storing different annotation layers in
separate
files) lacks mechanisms for analyzing relations between several annotation layers.
The Sekimo
Generic Format was developed for storing multiple annotated linguistic corpus data
and
examining relationships between elements derived from different annotation layers
in
a single file and therefore tries to use the benefits of standoff markup without
taking the before-mentioned problems into account.
A second design goal during the development of SGF was the possibility to reuse the
structure and features of existing annotation formats. SGF consists only of a base
layer which
serves as meta-markup language or as a container for standoff representations of the
original
inline annotations. In addition, the base layer supports storing of the primary data
(i.e.,
the data that is annotated), its segmentation, metadata regarding both the primary
data and
its annotation (either internally inside the SGF instance or via a reference to external
metadata resources), and provides SGF's log functionality (i.e. the possibility to
store an
instance's edit history). Segmentation of the primary data is application driven,
i.e. for
textual primary data usually a character based segmentation is established by importing
a
single inline annotation and computing the start and end positions of each annotation
element
(cf. section “Building XStandoff instances: inline2XF.xsl”). XML's inherent ID/IDREF mechnism is used for
linking between annotation elements and the corresponding segments of the primary
data which
are defined by SGF's segment element. Overlapping segments may occur and a single
character range (a segment) may be part of multiple annotation levels, reducing the
overall
amount of segments by eliminating duplicates. SGF is defined by a number of XML schema
files
containing embedded Schematron (ISO/IEC 19757-3:2006) assertions for additional
validation constraints and is available under the LGPL 3 license[3].Figure 7 shows a graphical overview of a prototypic SGF
instance's structure. Note that both corpus and corpusData are valid
root elements of an SGF instance allowing for storing single corpus entries or whole
corpora
in a single instance. Following Goecke et al., 2009 we differentiate between the
concept that serves as the background for the annotation (the level) and its XML serialization
(the layer). Elements drawn with dashed borders are optional (not every possible occurence
shown due to space restrictions), elements colored red do not belong to the SGF namespace
and
are shown for demonstration purposes only.
Figure 7: The structure of an SGF instance
Figure 8 shows the respective SGF instance containing both
annotation layers.
Figure 8: The SGF instance containing both syllable and morpheme annotation
SGF's main benefit with respect to other non-XML-based developments such as TexMECS
(cf.
Huitfeldt and Sperberg-McQueen, 2001) or the above-mentioned approaches is the usage of standard,
non-extended XML together with its accompanying technologies, such as XPath, XSLT
and XQuery.
We believe that this may be an argument when it comes to the sustainability aspect
of larger
corpora. In our project, we have developed a corpus consisting of 14 texts (both german
scientific and newspaper articles, 3,084 sentences, 56,203 tokens, 11,740 discourse
entities,
4,323 anaphoric relations in total), densely annotated on four different levels (logical
document structure, syntactic annotation, discourse entities and anaphoric relations).
A
partner project adopted SGF as export format for lexical chaining (SGF-LC, cf. Waltinger et al., 2008). In addition, it is used as import and export format of the web
based annotation tool Serengeti (cf. Stührenberg et al., 2007) and was chosen as one of the possible pivot formats for the
Anaphoric Bank (cf. http://www.anaphoricbank.org and Poesio et al., 2009). Cf.
Stührenberg and Goecke, 2008 and Witt et al., 2009a for a detailed discussion
of SGF and its use in analyzing the before-mentioned linguistic corpus.
The development of SGF to XStandoff
The version of SGF discussed in Stührenberg and Goecke, 2008 is considered as stable
version 1.0. However, work has begun on a forthcoming version addressing some minor
issues
– this developer version is called XStandoff (XStandoff version 1.1 internally,
although the final version number may change during the ongoing development process).
These
newer developments which are described in this section are accompanied by the creation
of
different tools which allow the broader use of XStandoff for the analysis of multi-dimensional
markup (discussed in section “The XStandoff toolkit”).
The changes made to the SGF's base layer can be divided into structural changes that
affect the compatibility between SGF 1.0 and XStandoff 1.1 instances (some of which
break the
compatibility – for this reason a new name and namespace was chosen) and changes
made in the underlying XML schemas that define the XStandoff meta format. XStandoff
1.1
supports external metadata via the newly introduced metaRef element which can be
used as child element of the corpus, corpusData,
resource, annotation, level, layer and
log elements as an alternative to the already established meta
element. Analogical, SGF's location element that has been used for providing a
reference to a file containing the primary data was dropped in favor of the new
primaryDataRef element. Both, metaRef and
primaryDataRef share the same globally defined RefType type
(together with the corpusDataRef and resourceRef elements) which
stores the attributes uri, encoding and mime-type,
improving the readability of the underlying XStandoff schema. The type attribute
which was located at the corpusData element in SGF and was used to differentiate
between textual and multimodal corpus entries was removed, since corpusData
elements containing multiple primaryDataRef children depicting primary data files
of different mime-types (e.g. video, audio and text files) should not have a singular
type.
The priority attribute was moved from the level element to the
layer element. The attribute has been used to prioritize annotation layers
(i.e. the XML serialization) in case of overlapping markup, therefore the re-arrangement
should clarify its application.
Other elements have been renamed: segments is now called
segmentation and the annotation element may only appear once at
most underneath a corpusData entry. SGF allowed several annotation
elements but since XStandoff supports multiple levels and layers, the annotation
element serves only as a wrapper similar to the segmentation element.
The XML schema for XStandoff's log functionality is now incorporated into XStandoff's
base
schema and can be considered as an integrated component of XStandoff's core functionality
(although it is still application-driven). Figure 9 shows the
resulting new structure. Again, keep in mind that the elements colored red do not
belong to
the XStandoff meta language.
Figure 9: The structure of an XStandoff instance
In general, valid SGF instances can be updated with little or no effort at all (depending
on the use of former optional attributes and elements) to fully comply to XStandoff.
Disjoints and continuous segments and containment and dominance
Annotating discontinuous or disjoint such as non-contiguous multi word expressions
or
separable verbs structures (e.g. in German) is a challenging task in XML (cf. Pianta and Bentivogli, 2004). Although it would be possible to use separate layers in XStandoff
to describe these structures as a workaround, disjoints and continuous segments are
supported natively. As a concrete example, take the well-known beginning of 'Alice
in
Wonderland' (cf. Sperberg-McQueen and Huitfeldt, 2008 for a general discussion of the
problems raised by discontinuity).
Alice was beginning to get very tired of sitting by her sister on the bank and of
having nothing to do: once or twice she had peeped into the book her sister was reading,
but it had no pictures or conversations in it, "and what is the use of a book," thought
Alice, "without pictures or conversations?"
The XStandoff instance of this example is shown in Figure 10.
Since both, p and q element belong to the logical document
structure level, only one level element is included. The quotation is annotated
as a q element constructed by the disjoint segment with the
identifier seg4 which itself uses the segments seg2 and seg3.
Figure 10: Disjoint segments in XStandoff
<xsf:corpusData xmlns="http://www.xstandoff.net/2009/xstandoff/1.1"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsf="http://www.xstandoff.net/2009/xstandoff/1.1"
xsi:schemaLocation="http://www.xstandoff.net/2009/xstandoff/1.1 ../xsd/xsf.xsd"
xsfVersion="1.1" xml:id="alice">
<xsf:primaryData start="0" end="302">
<textualContent>Alice was beginning to get very tired of sitting by her
sister on the bank and of having nothing to do: once or twice she had
peeped into the book her sister was reading, but it had no pictures or
conversations in it, "and what is the use of a book," thought Alice,
"without pictures or conversations?"</textualContent>
</xsf:primaryData>
<xsf:segmentation>
<xsf:segment xml:id="seg1" type="char" start="0" end="302"/>
<xsf:segment xml:id="seg2" type="char" start="218" end="250"/>
<xsf:segment xml:id="seg3" type="char" start="266" end="302"/>
<xsf:segment xml:id="seg4" type="seg" segments="seg2 seg3" mode="disjoint"/>
</xsf:segmentation>
<xsf:annotation>
<xsf:level xml:id="alice-log">
<xsf:layer xmlns:log="http://www.xstandoff.net/alice/log"
xsi:schemaLocation="http://www.xstandoff.net/alice/log ../xsd/alice-log.xsd"
priority="0">
<log:text xsf:segment="seg1">
<log:p xsf:segment="seg1">
<log:q xsf:segment="seg4"/>
</log:p>
</log:text>
</xsf:layer>
</xsf:level>
</xsf:annotation>
</xsf:corpusData>
Due to the differentiation between the annotation concept (the level) and its XML
representation (the layer), it is possible to sum up different XML serializations
underneath
the very same level element. XStandoff's layer element serves as a wrapper for
the slightly converted representation of the former inline annotation – the only
changes that are made concern the deletion of text nodes and the addition of the
segment attribute that links to the corresponding segment
element. The conversion applies to both the annotation instance and its underlying
XML
schema description (into which XStandoff's base layer is imported to add the
segment attribute to all element nodes as optional attribute) – the
latter can be used both for validating the original inline annotation and the converted
representation as part of the XStandoff instance. In contrast to other approaches
the
hierarchical structure of and the attributes included in the imported annotation layers
remain unchanged.
Other possible XStandoff instances include the separation of the q element
from the p layer at all (i.e. using separate layer elements which
is permitted by XStandoff), however, as already stated above, when dealing with disjoints
units, the inherent methods should be preferred.
Inline XStandoff
In contrast to SGF, XStandoff supports a newly introduced inline representation (cf.
Section section “Building inline XStandoff annotations: XSF2inline.xsl”), containing the virtual root element
inline and the generic milestone element (modelled according to
the respective TEI element, cf. Burnard and Bauman, 2008). During the Sekimo project
Schiller's 'Die Bürgschaft' was annotated on the following annotation levels: words,
morphemes, syllables, verse, prose and phrase[4]. We've converted these six levels into a single XStandoff instance[5]. The inline representation shown in Figure 13 was
generated afterwards (cf. section “Demonstration: Creating an inline XStandoff annotation”).
Figure 13: Part of the inline XStandoff instance of Schiller's 'Die Bürgschaft' annotated on
six
levels.
Since each single annotation layer contains a text root element, a
body and a head element, these elements occur six times in the
resulting XStandoff instance. It should be noted, that in this case the inline XStandoff
instance is more than two-thirds bigger in size than the 'classic' (i.e. standoff)
XStandoff
instance (763.9 KB vs. 452.5 KB) and is far from being easily readable.
Introducing the 'all' namespace
For both 'classic' XStandoff and especially for inline XStandoff instances, a new
namespace – http://www.xstandoff.net/2009/all – was
introduced. Elements belonging to this namespace do not only share the same range
of
characters but the generic identifier and are present in all annotation layers (e.g.
the
above mentioned text root element). Figure 14 shows
the same part of the inline XStandoff instance using the newly introduced namespace.
Note
that the a attribute of the text element of the verse layer
remains intact. Cf. Figure 19 in section “Demonstration: Creating an inline XStandoff annotation” for an
extended excerpt.
Figure 14: Excerpt of the inline XStandoff instance of Schiller's 'Die Bürgschaft' using the
all namespace.
This mechanism allows for a better readability of a multi-dimensional annotated inline
XStandoff instance. However, one should be aware that the all namespace should only be used when the respective elements not only bear
the same generic identifier and character range but also the same semantic value.
Note that the inline XStandoff instance lacks the support for validation of
multi-dimensional annotations that is present in 'classic' XStandoff instances and
should be
therefore considered for demonstration purposes only.
The XStandoff toolkit
In the context of XStandoff's development several XSLT 2.0 stylesheets (cf. Kay, 2007, Kay 2008) have been created which allow for the
convenient generation and editing of XStandoff files[6]. Since there are no product specific extensions, transformations should be able to
be executed by every XSLT processor supporting XSLT 2.0. The transformations during
the test
phase of the stylesheets have been performed by the Saxon XSLT processor which is
available
both as Open Source version Saxon-B and as optimized, schema-aware, commercial version
Saxon-SA[7].
Currently the XStandoff toolkit consists of four stylesheets which perform basic
processing of XStandoff instances. They are responsible for the conversion of a single
inline
annotation to XStandoff, the merging of XStandoff annotation layers corresponding
to the same
primary data, the removing of single layers from an XStandoff file and, the conversion
of an
XStandoff instance to an XStandoff inline annotation (cf. section “The development of SGF to XStandoff”).
These tasks might seem simple, but as you will see it would hardly be possible to
perform them
manually.
Building XStandoff instances: inline2XF.xsl
At the moment the easiest way of building XStandoff files is to transform an inline
annotation into XStandoff by the stylesheet inline2XSF.xsl.
This excludes the coverage of overlapping markup at first sight because of the inline
annotation not including such structures. But we will show how to include more than
one
inline annotation into a single XStandoff file by merging several XStandoff annotations
(cf.
section “Merging XStandoff instances: mergeXSF.xsl”). By this means overlapping structures can be
covered.
The transformation into XStandoff requires an input XML file ideally containing elements
bound by XML namespaces. Every single namespace evokes the output of a layer in XStandoff
which contains the elements of the namespace. Thereby the default (or empty) namespace
is
treated like the named ones. Thus inline annotations without explicit namespace declarations
can also be processed (in this case a namespace will be generated).
The process of converting an inline annotation to XStandoff is divided into two steps:
Firstly, segments are built on the basis of the occurring elements. There are two
possible
ways of mapping the element boundaries to the textual content in the form of character
positions. The preferred way of reaching such a mapping is the use of a primary data
file
which contains the bare text without annotations. The name of this file can be provided
during the transformation call by specifying the stylesheet parameter primary-data. Providing the location of a primary data file leads to a
comparison of the content of the primary data file and the textual content of the
input file
of the transformation. This guarantees primary data identity. If no primary data location
is
provided, the textual content of the input file is used to build up the primary data.
This
has certain disadvantages such as the lack of line breaks since these cannot easily
be
inferred by the textual content of an XML file. Furthermore, the automatic conversion
of the
textual content of the input file to be used as primary data relies on heuristics
which have
to detect white space characters. Because of the complexity of this task it is possible
to
get undesirable results.
After the building of segments, the second step of the transformation is to return
layers on the basis of namespaces. Thus for every namespace the corresponding elements
are
released from the initial inline annotation and copied into the layer maintaining
the
embedding relations. Meanwhile the elements in the XStandoff layer get connected to
the
according segments by ID/IDREF binding. In this manner one segment can serve as a
reference
for elements from different layers.
There are several additional optional parameters which can control certain aspects
of
the transformation from inline to XStandoff. The most important of them will be briefly
outlined below.
Specifies a unique element (if no error occurs) which serves as the starting point
of the conversion of the input file. By default the whole file will be converted
starting at the document root.
This parameter determines the location of metadata in the input XML document (if
any). By this means it can be copied into the XStandoff instance. Analogous to the
parameter virtual-root an element name is expected as a value of meta-root.
Determines whether the corresponding XStandoff XML Schema files are stored locally
or shall be taken from the WWW (i.e. from
http://www.xstandoff.net/2009/xstandoff/1.1). By default the global XSDs
are used.
XStandoff uses segments for referencing units of the primary data annotated in one
or more annotation layers. Additional segments for non-character data (i.e. white
space
characters, such as blanks, line breaks, etc.) can be computed and returned by the
stylesheet as well if the parameter include-ws-segments is set to '1'.
The output of an 'all-layer' (cf. section “Inline XStandoff”) containing
elements present in all annotation layers depends on the specification of this
parameter. By default its value is set to '0' which avoids the transfer of the
respective elements into the 'all-layer' (cf. section “Introducing the 'all' namespace”).
Merging XStandoff instances: mergeXSF.xsl
Due to the frequent use of the ID/IDREF mechanism in XStandoff for establishing
connections between segment elements (i.e. the limits of the respective text
span in the primary data's character stream) and the corresponding annotation, manually
merging XStandoff files seems quite unpromising. The XSLT stylesheet
mergeXSF.xsl transforms two XStandoff instances into a single one containing
the annotation levels (or layers) from both input files. The first XStandoff file
is
provided as the input file of the transformation, the second file's name has to be
included
via the stylesheet parameter merge-with.
The main problem is to adapt the segments from the involved XStandoff files to each
other. On the one hand there are segments in the different files spanning over the
same
string of the primary data, but having distinct IDs. In this case the two segments
have to
be replaced by one. On the other hand there will be segments with the same ID, but
spanning
over different character positions. These have to get new unique IDs. The merging
of the
XStandoff files in general leads to a complete reorganization of the segment list
making it
necessary to update the segment references of the elements in the XStandoff layers.
After
fulfilling this duty, the XStandoff layers are included in the new XStandoff file.
The reorganization of the segment list can be disabled by configuring the stylesheet
parameter keep-segments. Specifying the value '1' causes
the perpetuation of the segments of the input XStandoff file. However, the segments
of the
file provided by the merge-with parameter are always
subject to a reorganization.
In addition, the stylesheet handles the optional output of the 'all-layer'. Setting
the
value of the all-layer parameter to '1' evokes the
inclusion of this special layer containing the elements that are present in every
single
annotation layer. It is irrelevant if there was an 'all-layer' present in the input
files or
not. Though it might happen that no such layer is returned, namely if there are no
elements
in the several layers which share the required features.
Currently the stylesheet only supports the merging of two single XStandoff files.
Naturally this allows for a successive merging of more than two files. However it
would be
more straightforward to have the possibility of merging more than two XStandoff files
during
a single transformation. A future version of the stylesheet supporting multi-file-merge
is
in preparation.
Deleting parts of XStandoff instances: removeXSFcontent.xsl
For deletion of parts of an XStandoff instance the stylesheet removeXSFcontent.xsl can be applied. During the transformation call one has to
supply the ID of the element to be deleted (either level or layer)
via the value of the remove-ID parameter. The matching
element is removed from the XStandoff file and the list of segments is updated, i.e.
the
segments which solely were referenced by descendant elements of the mentioned element
are
excluded. This, admittedly, again leads to a reorganzation of the segments since these
by
default get a continuous numbering.
Similar to the usage of the mergeXSF.xsl stylesheet the
reorganization of the segments can be disabled by the stylesheet parameter keep-segments. The value '1' lets the stylesheet keep the old
segments, but without those only referenced by descendant elements of the deleted
element.
Furthermore, the removed XStandoff content can be returned in a separate file.
Specifying the value '1' for the stylesheet parameter return-removed will encourage the stylesheet to return the removed content
into a new XStandoff instance. Accordingly, the new file will contain the segments
referenced by elements of the removed content and the removed content itself.
Building inline XStandoff annotations: XSF2inline.xsl
In addition to the inline2XSF.xsl stylesheet there is a
counterpart. XSF2inline.xsl creates an inline annotation on
the basis of an XStandoff instance. The approach covers the handling of overlapping
markup
insofar as these structures are represented by milestone elements in the resulting
inline
annotation (cf. Figure 13 in section “The development of SGF to XStandoff”).
Concerning this matter, the first task of the stylesheet is to detect segments whose
start
and end position information constitute an overlap. These segments are split up into
segments representing milestones so that they can be used as an adequate basis to
build an
inline annotation. The linear list of segments is processed recursively by taking
the
currently outermost segments (those who are not included in other segments' spans
which
respectively are determined by their start and end positions in the character range
of the
primary data). The elements of the XStandoff layers which are referenced by the outermost
segments are copied into the inline annotation. The segments which are embedded in
the
outermost segments are processed recursively.
However, copying the elements from the XStandoff layers has to be controlled by a
mechanism regarding the possibility of elements from different layers referencing
the same
segment. These elements share the same positions for start and end tags and therefore
a
decision has to be made in which order they should be nested into one another. The
optional
stylesheet parameter sort-by refers to this circumstance.
Its default value is 'measure' which means that a statistical analysis is performed
by the
stylesheet that diagnoses the embedding relations of all occuring element types by
frequency. An expected result would be that elements representing sentence boundaries
are
embedded into those for paragraphs because this embedding relation is more frequent
than
vice versa. The only case this approach could be inadequate for are
elements of different layers for which no definite statistical result for embedding
can be
achieved. For instance, there could be elements whose boundaries always share the
same
character positions, but which can clearly semantically be assigned to a certain embedding.
This case cannot be covered by the statistical method.
In addition, the embedding can be based on the priority attribute of the
level (in SGF version 1.0) or the layer (in XStandoff version
1.1, cf. section “The development of SGF to XStandoff”) element. This strategy can be accessed by
specifying the value 'priority' for the parameter sort-by.
Low values of the priority attribute in the XStandoff annotation are nested
deeper in the inline annotation than higher ones. By this means the user can specify
the
embedding manually, but one has to be sure to set the values of the attribute correctly
to
get the desired result. This method underlies the assumption that there can be a
semantically grounded, definite decision for the embedding. The most promising concept
was a
mixture of the both approaches which has to be realized in future work.
There is an additional optional stylesheet parameter return-segID which can be very helpful to retain a connection between the
XStandoff file and the resulting inline annotation. By default the value of this parameter
is set to '1' which means that the segment attribute is retained throughout the
conversion process. The parameter has been added mainly for control issues.
Demonstration: Creating an inline XStandoff annotation
In this section the conversion of six original annotations into one inline XStandoff
annotation will be outlined. This will demonstrate the function and execution of the
several
XSLT stylesheets which are involved in this process. An extract of the final result
of the
conversion process can be seen in section “Inline XStandoff” where the inline
XStandoff annotation was introduced.
There are three major steps in order to create one inline XStandoff annotation out
of
the six input annotations:
Applying the stylesheet inline2XSF.xsl to each input annotation
Successively merging the resulting standoff XStandoff files into one with
mergeXSF.xsl
Creating an inline XStandoff instance via the stylesheet XSF2inline.xsl
Applying inline2XSF.xsl
The six original annotation files are given by different annotations of Schiller's
'Die Bürgschaft' which cover several linguistic fields: words, morphemes, syllables,
verse, prose and phrase.[8]
Figure 15 shows an extract of one of the original annotations. In
case of missing namespaces these are created automatically by the stylesheet. For
the sake
of readability the namespace prefix 'wort' was added to the elements derived from
this
namespace.
Figure 15: The original word level annotation of 'Die Bürgschaft'
(buergschaft-wort.xml)
The corresponding primary data file buergschaft-pd.txt has the following plain text
content:
Figure 16: Primary data of 'Die Bürgschaft' (buergschaft-pd.txt)
Die Bürgschaft Friedrich Schiller
Zu Dionys dem Tirannen schlich Damon, den Dolch im Gewande, Ihn schlugen (...)
The result of the invoked transformation (saxon buergschaft-wort.xml
inline2XSF.xsl primary-data=buergschaft-pd.txt) is an XStandoff instance
containing the converted annotation including references to the respective spans in
the
primary data's character stream defined by the segments elements (cf. Figure 17).
Figure 17: The converted word level annotation of 'Die Bürgschaft'
(buergschaft-wort-xsf.xml)
The other five input annotations are transformed analogously, serving as
the basis for the next processing step: the application of the mergeXSF stylesheet.
Merging XStandoff instances
As mentioned above, several different XStandoff instances relying on the same primary
data can be combined into a single XStandoff file. However, it is not yet possible
to
integrate the respective annotation levels and layers within a single transformation
call.
In order to get a single result instance, one has to use five calls in total. The
first
call merges two of the instances (e.g. saxon -o <RESULT>.xml
buergschaft-wort-xsf.xml mergeXSF.xsl merge-with=buergschaft-silbe-xsf.xml
all-layer=1).
The next four transformation calls merge the result
(<RESULT>.xml from the previous call) with the single
remaining XStandoff instances. Due to the stylesheet parameter all-layer which is set to 1 in the call, the result will
contain a layer which stores those elements present in all layers (cf. section “Merging XStandoff instances: mergeXSF.xsl”). Figure 18 shows an extract of the
result of the five mergeXSF transformations.
Figure 18: The merged XStandoff annotation of 'Die Bürgschaft'
(buergschaft-wort-prosa-silbe-vers-phrase-morphem-xsf.xml)
The last step which has to be applied in order to get an inline XStandoff annotation
created from the six original input annotations is the transformation done by the
stylesheet XSF2inline.xsl (saxon -o <RESULT>.xml
buergschaft-wort-prosa-silbe-vers-phrase-morphem-xsf.xml XSF2inline.xsl).
Overlaps which may occur, are covered by insertion of the newly introduced
milestone element.
Figure 19: The inline XStandoff annotation of 'Die Bürgschaft'
(buergschaft-wort-prosa-silbe-vers-phrase-morphem-inline.xml)
Note that the above listing contains the representation of an overlap. Since morpheme
and syllable level contain concurring annotations
(<morphem:m>Tiran<silbe:syll>n</morphem:m>en</silbe:syll>)
milestone elements have been added to mark the original boundaries of the morphem:m
element.
Analyzing cross-level relations with XStandoff and XQuery
Since XStandoff is a meta language based on standard XML, a variety of XML processing
tools may be used. In addition to the XStandoff toolkit an XQuery script is available
as a
first starting point for analyzing relations between elements derived from different
annotation levels (and layers respectively). The query takes a valid XStandoff instance
as
input and demands to provide a target element on an included layer which is used as
starting
point for the finding of relations to other elements derived on different annotation
layers.
For this example we have chosen the English translation of Brothers Grimm's 'The three
lazy
ones' which was annotated with two different linguistic parsers: the freely available
TreeTagger[9] and the POS tagger that is part of the eHumanities Desktop[10] which can be used at no charge as an online resource (cf. Gleim et al., 2009). The resulting XStandoff instance can be downloaded at http://www.xstandoff.net/examples/grimm.html. The output of the query contains the
target element and the corresponding elements on other layers, starting with elements
that share
the same segment (and share therefore the identical text span in the primary data).
The
relations identified by the XQuery are based on the work done by Durusau and O'Donnell, 2002. An excerpt of the output can be seen in Figure 20.
Figure 20: Excerpt of the output of the XQuery applied to the 'The three lazy ones'
In this example the eHD:w element (derived from eHumanities Desktop's
tagger) is used as target element. An element that shares the same segment of the
primary data
is the tree:token element (marked as identical element) derived from
the TreeTagger parse. Since the target element is the first element other elements
share the
same starting point, such as eHD:text, eHD:body,
eHD:div, eHD:p and eHD:s (on the same layer) and
tree:corpus (derived from the TreeTagger output). The second target element
(the second eHD:w element) is again identical to the tree:token element, and is
included (in the sense of containment, cf. section “Disjoints and continuous segments and containment and dominance”) by a variety of
other elements.
In this scenario XStandoff can be used for different purposes: for comparing different
linguistic resources' output in terms of both quality and quantity of the annotation,
for
refining and boosting overall annotation performance by combining several resources,
and of
course for analyzing virtual parenthoods between elements derived from different annotation
layers (cf. Stührenberg and Goecke, 2008 for a real-world example).
Conclusion and Future Work
We have demonstrated both the further developments that have been made to the Sekimo
Generic Format, resulting in XStandoff, and the respective XSLT stylesheets that can
be used
to generate and modify XStandoff instances. It is planned that XStandoff's current
development
version will be finished as a stable version in time with XML Schema 1.1 which is
in the
Working Draft status at the time of writing (XML Schema 1.1 Part 1, 2009) and which would
allow us to dismiss the embedded Schematron assertions. Regarding the XSLT part of
the
XStandoff toolkit, future enhancements are supposable in the support of the
containment/dominance feature and since the creation of XStandoff instances is a multi-step
process (cf. section “Demonstration: Creating an inline XStandoff annotation”), providing an XProc pipeline (cf. XProc 2009) is another future option. Further perspectives include the building
of a corpus of multi-dimensional annotated (and possibly overlapping) markup for further
developments regarding both XStandoff's specification and the respective XSLT stylesheets
(a
starting point has been made at http://www.xstandoff.net/examples/index.html). This corpus should be gathered
together with other interested parties, e.g. the Markup Languages for Complex Documents
(MLCD)
project, the XCONCUR developers and the LMNL community. Alternative XQuery realizations
of the
discussed XSLT stylesheets should give clues about further optimizations regarding
the
processing times (cf. Stührenberg and Goecke, 2008 for a small test example). In
addition, it would be promising to share our developments with the framework for format
translations described by Marinelli et al., 2008.
Although XStandoff's formal model is considered as multi-rooted tree – at least
if one restricts oneself to not using discontinous segments – additional future work
has to be made regarding its expressiveness compared to other approaches, including
GODDAG
structures (cf. Sperberg-McQueen and Huitfeldt, 2004, Sperberg-McQueen and Huitfeldt, 2008a, Marcoux 2008 and Marcoux 2008a) and LMNL. This holds
especially for an examination of the containment and dominance relations described
in Sperberg-McQueen and Huitfeldt, 2008 but also to other formal aspects of concurrent
markup.
References
[Alink et al., 2006] Alink, W., Bhoedjang, R., de
Vries, A. P., and Boncz, P. A. Efficient XQuery Support for Stand-Off
Annotation. In: Proceedings of the 3rd International Workshop on XQuery
Implementation, Experience and Perspectives, in cooperation with ACM SIGMOD, Chicago,
USA,
2006
[Alink et al., 2006a] Alink, W., Jijkoun, V., Ahn,
D., and de Rijke, M. Representing and Querying Multi-dimensional Markup
for Question Answering. In: Proceedings of the 5th EACL Workshop on NLP and XML
(NLPXML-2006): Multi-Dimensional Markup in Natural Language Processing, Trento,
2006
[Bird and Liberman, 1999] Bird, S. and Liberman, M.
Annotation graphs as a framework for multidimensional linguistic data
analysis. In: Proceedings of the Workshop "Towards Standards and Tools for
Discourse Tagging", pages 1–10. Association for Computational Linguistics, 1999
[Bird et al., 2006] Bird, S., Chen, Y., Davidson, S.,
Lee, H. and Zheng,Y. Designing and Evaluating an XPath Dialect for
Linguistic Queries. In: Proceedings of the 22nd International Conference on Data
Engineering (ICDE), Atlanta, USA, 2006. doi:https://doi.org/10.1109/ICDE.2006.48
[Burnard and Bauman, 2008] Burnard, L., and Bauman,
S. (eds.). TEI P5: Guidelines for Electronic Text Encoding and
Interchange. published for the TEI Consortium by Humanities Computing Unit,
University of Oxford, Oxford, Providence, Charlottesville, Nancy, 2008
[Carletta et al., 2003] Carletta, J., Kilgour, J.,
O’Donnel, T. J., Evert, S. and Voormann, H. The NITE Object Model
Library for Handling Structured Linguistic Annotation on Multimodal Data Sets.
In: Proceedings of the EACL Workshop on Language Technology and the Semantic Web (3rd
Workshop
on NLP and XML (NLPXML-2003)), Budapest, Ungarn, 2003
[Cowan et al., 2006] Cowan, J., Tennison J., and Piez,
W. LMNL update. In: Proceedings of Extreme Markup Languages,
Montréal, Québec, 2006
[DeRose, 2004] DeRose, S. J. Markup Overlap: A Review and a Horse. In: Proceedings of Extreme Markup
Languages, Montréal, Québec, 2004
[Dipper, 2005] Dipper, S. XML-based stand-off representation and exploitation of multi-level linguistic
annotation. In: Proceedings of Berliner XML Tage 2005 (BXML 2005), pages 39–50,
Berlin, Germany, 2005
[Dipper et al., 2007] Dipper, S., Götze, M., Küssner,
U. and Stede, M. Representing and Querying Standoff XML. In:
Rehm, G., Witt, A. and Lemnitzer, L. (eds.), Datenstrukturen für linguistische Ressourcen
und
ihre Anwendungen. Data Structures for Linguistic Resources and Applications. Proceedings
of
the Biennial GLDV Conference 2007, pages 337–346, Tübingen, 2007. Gunter Narr
Verlag
[Durusau and O'Donnell, 2002] Durusau, P. and
O'Donnell, M.B.. Concurrent Markup for XML Documents. In:
Proceedings of the XML Europe conference 2002.
[Durusau and O'Donnel, 2004] Durusau, P. &
O'Donnel, M. B. Tabling the Overlap Discussion. In:
Proceedings of Extreme Markup Languages, Montréal, Québec, 2004
[Goecke et al., 2009] Goecke, D., Lüngen, H.,
Metzing, D., Stührenberg, M. and Witt, A. Different Views on Markup.
Distinguishing levels and layers. In: Linguistic modeling of information and
Markup Languages. Contributions to language technology. Springer, 2009. To
appear
[Gleim et al., 2009] Gleim, R., Waltinger, U., Ernst,
A., Mehler, A., Esch, D., and Feith, T. The eHumanities Desktop
– An Online System for Corpus Management and Analysis in Support of Computing in
the Humanities. In: Proceedings of the Demonstrations Session of the 12th
Conference of the European Chapter of the Association for Computational Linguistics
EACL 2009,
30 March – 3 April, Athens, 2009
[Huitfeldt and Sperberg-McQueen, 2001] Huitfeldt,
C. and Sperberg-McQueen, C. M. TexMECS: An experimental markup
meta-language for complex documents. Markup Languages and Complex Documents
(MLCD) Project, February 2001
[Iacob and Dekhtyar, 2005] Iacob, I. E. and Dekhtyar,
A. Processing XML documents with overlapping hierarchies In:
JCDL '05: Proceedings of the 5th ACM/IEEE-CS joint conference on Digital libraries,
ACM Press,
2005, pages 409-409. doi:https://doi.org/10.1145/1065385.1065513
[Iacob and Dekhtyar, 2005a] Iacob, I. E. and
Dekhtyar, A. Towards a Query Language for Multihierarchical XML:
Revisiting XPath. In: Proceedings of the 8th International Workshop on the Web
& Databases (WebDB 2005), 2005, pages 49-54
[Ide and Romary, 2007] Ide, N. and Romary, L. Towards International Standards for Language Resources. In: Dybkjaer,
L., Hemsen, H., and Minker, W., (eds.), Evaluation of Text and Speech Systems, pages
263-284.
Springer
[Ide and Suderman, 2007] Ide, N. and Suderman, K.
GrAF: A Graph-based Format for Linguistic Annotations. In:
Proceedings of the Linguistic Annotation Workshop, pages 1-8, Prague, Czech Republic.
Association for Computational Linguistics, 2007
[ISO/IEC 19757-2:2003] ISO/IEC 19757-2:2003. Information technology – Document Schema Definition Language (DSDL) –
Part 2: Regular-grammar-based validation – RELAX NG (ISO/IEC 19757-2).
International Standard, International Organization for Standardization, Geneva,
2003
[ISO/IEC 19757-3:2006] ISO/IEC 19757-3:2006.
Information technology – Document Schema Definition Language (DSDL)
– Part 3: Rule-based validation – Schematron. International standard,
International Organization for Standardization, Geneva, 2006
[Jagadish et al., 2004] Jagadish, H. V.,
Lakshmanany, L. V. S., Scannapieco, M., Srivastava, D. and Wiwatwattana, N. Colorful XML: One hierarchy isn’t enough. In: Proceedings of ACM
SIGMOD International Conference on Management of Data (SIGMOD 2004), pages 251–262,
Paris,
June 13-18 2004. ACM Press New York, NY, USA. doi:https://doi.org/10.1145/1007568.1007598
[Kay, 2007] Kay, M. XSL
Transformations (XSLT) Version 2.0. World Wide Web Consortium. 2007. –
W3C Recommendation
[Kay 2008] Kay, M. XSLT 2.0 and
XPath 2.0 Programmer’s Reference. Wiley Publishing, Indianapolis, 4th edition,
2008
[Marcoux 2008] Marcoux, Y. Graph characterization of overlap-only texmecs and other overlapping markup
formalisms. In: Proceedings of Extreme Markup Languages, Montréal, Québec,
2008
[Marcoux 2008a] Marcoux, Y. Variants of GODDAGs and suitable first-layer semantics. Presentation given at the
GODDAG workshop, Amsterdam, 1-5 December 2008
[Pianta and Bentivogli, 2004] Pianta, E. and
Bentivogli., L. Annotating Discontinuous Structures in XML: the
Multiword Case. In: Proceedings of LREC 2004 Workshop on ”XML-based richly
annotated corpora”, pages 30–37, Lisbon, Portugal.
[Poesio et al., 2009] Poesio, M., Diewald, N.,
Stührenberg, M., Chamberlain, J., Jettka, D., Goecke, D. and Kruschwitz, U. Markup Infrastructure for the Anaphoric Bank, Part I: Supporting Web
Collaboration. In: Mehler, A., Kühnberger, K.-U., Lobin, H., Lüngen, H., Storrer,
A. and Witt, A. (eds.), Modelling, Learning and Processing of Text Technological Data
Structures, Dordrecht: Springer, Berlin, New York. To appear
[Schonefeld, 2007] Schonefeld, O. XCONCUR and XCONCUR-CL: A constraint-based approach for the validation of
concurrent markup. In: Rehm, G., Witt, A., Lemnitzer, L. (eds.), Datenstrukturen
für linguistische Ressourcen und ihre Anwendungen. Data Structures for Linguistic
Resources
and Applications. Proceedings of the Biennial GLDV Conference 2007, Tübingen, Germany,
2007.
Gunter Narr Verlag
[Sperberg-McQueen et al., 2002] Sperberg-McQueen, C. M., Dubin, D., Huitfeldt, C. and Renear, A. Drawing inferences on the basis of markup. In: Proceedings of Extreme Markup
Languages, 2002
[Sperberg-McQueen and Huitfeldt, 2004] Sperberg-McQueen, C. M. and Huitfeldt, C. GODDAG: A Data Structure for
Overlapping Hierarchies. In: King, P. and Munson, E. V. (eds.), Proceedings of
the 5th International Workshop on the Principles of Digital Document Processing (PODDP
2000),
volume 2023 of Lecture Notes in Computer Science, pages 139–160. Springer, 2004
[Sperberg-McQueen, 2006] Sperberg-McQueen,
C. M. Rabbit/Duck grammars: a validation method for overlapping
structures. In: Proceedings of Extreme Markup Languages, Montréal, Québec,
2006
[Sperberg-McQueen, 2007] Sperberg-McQueen,
C. M. Representation of overlapping structures. In:
Proceedings of Extreme Markup Languages, Montréal, Québec, 2007
[Sperberg-McQueen and Huitfeldt, 2008] Sperberg-McQueen, C. M. and Huitfeldt, C. Markup Discontinued
Discontinuity in TexMecs, Goddag structures, and rabbit/duck grammars. Presented at Balisage: The Markup Conference 2008, Montréal, Canada, August 12 -
15, 2008. In: Proceedings of Balisage: The Markup Conference 2008. Balisage Series
on Markup Technologies, vol. 1 (2008). doi:https://doi.org/10.4242/BalisageVol1.Sperberg-McQueen01
[Stührenberg et al., 2007] Stührenberg, M.,
Goecke, D, Diewald, N., Cramer, I. and Mehler, A. Web-based annotation
of anaphoric relations and lexical chains. In: Proceedings of the Linguistic
Annotation Workshop (LAW), pages 140–147, Prague. Association for Computational Linguistics,
2007
[Stührenberg and Goecke, 2008] Stührenberg, M.
and Goecke, D.SGF – An integrated model for multiple
annotations and its application in a linguistic domain. Presented at Balisage: The Markup Conference 2008, Montréal, Canada, August 12 -
15, 2008. In: Proceedings of Balisage: The Markup Conference 2008. Balisage Series
on Markup Technologies, vol. 1 (2008). doi:https://doi.org/10.4242/BalisageVol1.Stuehrenberg01
[Tennison, 2002] Tennison, J. Layered Markup and Annotation Language (LMNL). In: Proceedings of Extreme Markup
Languages, Montréal, Québec, 2002
[Tennison, 2007] Tennison, J. Creole: Validating Overlapping Markup.In: Proceedings of XTech 2007: The
Ubiquitous Web Conference, 2007
[Thompson and McKelvie, 1997] Thompson, H. S. and
D. McKelvie. Hyperlink semantics for standoff markup of read-only
documents. In: Proceedings of SGML Europe ’97: The next decade – Pushing the
Envelope, pages 227–229, Barcelona, 1997
[Waltinger et al., 2008] Waltinger, U., Mehler, A.
Mehler, and Stührenberg, M. An Integrated Model of Lexical Chaining:
Application, Resources and its Format. Proceedings of the 9th Conference on
Natural Language Processing (KONVENS 2008)
[XProc 2009] Walsh, N., Milowski, A., and Thompson, H.
S. (2009). XProc: An XML Pipeline Language. W3C Candidate Recommendation 28 May 2009,
World
Wide Web Consortium.
[Witt, 2002] Witt, A. Meaning
and interpretation of concurrent markup. In: Proceedings of ALLC-ACH2002, Joint
Conference of the ALLC and ACH, 2002
[Witt, 2004] Witt, A. Multiple
hierarchies: New Aspects of an Old Solution. In: Proceedings of Extreme Markup
Languages, 2004
[Witt et al., 2009] Witt, A., Rehm, G., Hinrichs, E.,
Lehmberg, T. and Stegmann, J. SusTEInability of Linguistic Resources through Feature
Structures. In: Literary and Linguistic Computing, 24(3): pages 363-372, 2009. doi:https://doi.org/10.1093/llc/fqp024
[Witt et al., 2009a] Witt, A., Stührenberg, M.,
Goecke, D. and Metzing, D. Integrated Linguistic Annotation Models and
their Application in the Domain of Antecedent Detection. In: Mehler, A.,
Kühnberger, K.-U., Lobin, H., Lüngen, H., Storrer, A. and Witt, A. (eds.), Modelling,
Learning
and Processing of Text Technological Data Structures, Dordrecht: Springer, Berlin,
New York.
To appear
Alink, W., Bhoedjang, R., de
Vries, A. P., and Boncz, P. A. Efficient XQuery Support for Stand-Off
Annotation. In: Proceedings of the 3rd International Workshop on XQuery
Implementation, Experience and Perspectives, in cooperation with ACM SIGMOD, Chicago,
USA,
2006
Alink, W., Jijkoun, V., Ahn,
D., and de Rijke, M. Representing and Querying Multi-dimensional Markup
for Question Answering. In: Proceedings of the 5th EACL Workshop on NLP and XML
(NLPXML-2006): Multi-Dimensional Markup in Natural Language Processing, Trento,
2006
Bird, S. and Liberman, M.
Annotation graphs as a framework for multidimensional linguistic data
analysis. In: Proceedings of the Workshop "Towards Standards and Tools for
Discourse Tagging", pages 1–10. Association for Computational Linguistics, 1999
Bird, S., Chen, Y., Davidson, S.,
Lee, H. and Zheng,Y. Designing and Evaluating an XPath Dialect for
Linguistic Queries. In: Proceedings of the 22nd International Conference on Data
Engineering (ICDE), Atlanta, USA, 2006. doi:https://doi.org/10.1109/ICDE.2006.48
Burnard, L., and Bauman,
S. (eds.). TEI P5: Guidelines for Electronic Text Encoding and
Interchange. published for the TEI Consortium by Humanities Computing Unit,
University of Oxford, Oxford, Providence, Charlottesville, Nancy, 2008
Carletta, J., Kilgour, J.,
O’Donnel, T. J., Evert, S. and Voormann, H. The NITE Object Model
Library for Handling Structured Linguistic Annotation on Multimodal Data Sets.
In: Proceedings of the EACL Workshop on Language Technology and the Semantic Web (3rd
Workshop
on NLP and XML (NLPXML-2003)), Budapest, Ungarn, 2003
Carletta, J.; Evert, S.;
Heid, U. and Kilgour, J. The NITE XML Toolkit: data model and query
language. In: Language Resources and Evaluation, Springer, Dordrecht, 2005, 39,
pages 313-334. doi:https://doi.org/10.1007/s10579-006-9001-9
Dipper, S. XML-based stand-off representation and exploitation of multi-level linguistic
annotation. In: Proceedings of Berliner XML Tage 2005 (BXML 2005), pages 39–50,
Berlin, Germany, 2005
Dipper, S., Götze, M., Küssner,
U. and Stede, M. Representing and Querying Standoff XML. In:
Rehm, G., Witt, A. and Lemnitzer, L. (eds.), Datenstrukturen für linguistische Ressourcen
und
ihre Anwendungen. Data Structures for Linguistic Resources and Applications. Proceedings
of
the Biennial GLDV Conference 2007, pages 337–346, Tübingen, 2007. Gunter Narr
Verlag
Goecke, D., Lüngen, H.,
Metzing, D., Stührenberg, M. and Witt, A. Different Views on Markup.
Distinguishing levels and layers. In: Linguistic modeling of information and
Markup Languages. Contributions to language technology. Springer, 2009. To
appear
Gleim, R., Waltinger, U., Ernst,
A., Mehler, A., Esch, D., and Feith, T. The eHumanities Desktop
– An Online System for Corpus Management and Analysis in Support of Computing in
the Humanities. In: Proceedings of the Demonstrations Session of the 12th
Conference of the European Chapter of the Association for Computational Linguistics
EACL 2009,
30 March – 3 April, Athens, 2009
Huitfeldt,
C. and Sperberg-McQueen, C. M. TexMECS: An experimental markup
meta-language for complex documents. Markup Languages and Complex Documents
(MLCD) Project, February 2001
Iacob, I. E. and Dekhtyar,
A. Processing XML documents with overlapping hierarchies In:
JCDL '05: Proceedings of the 5th ACM/IEEE-CS joint conference on Digital libraries,
ACM Press,
2005, pages 409-409. doi:https://doi.org/10.1145/1065385.1065513
Iacob, I. E. and
Dekhtyar, A. Towards a Query Language for Multihierarchical XML:
Revisiting XPath. In: Proceedings of the 8th International Workshop on the Web
& Databases (WebDB 2005), 2005, pages 49-54
Ide, N. and Romary, L. Towards International Standards for Language Resources. In: Dybkjaer,
L., Hemsen, H., and Minker, W., (eds.), Evaluation of Text and Speech Systems, pages
263-284.
Springer
Ide, N. and Suderman, K.
GrAF: A Graph-based Format for Linguistic Annotations. In:
Proceedings of the Linguistic Annotation Workshop, pages 1-8, Prague, Czech Republic.
Association for Computational Linguistics, 2007
ISO/IEC 19757-2:2003. Information technology – Document Schema Definition Language (DSDL) –
Part 2: Regular-grammar-based validation – RELAX NG (ISO/IEC 19757-2).
International Standard, International Organization for Standardization, Geneva,
2003
ISO/IEC 19757-3:2006.
Information technology – Document Schema Definition Language (DSDL)
– Part 3: Rule-based validation – Schematron. International standard,
International Organization for Standardization, Geneva, 2006
Jagadish, H. V.,
Lakshmanany, L. V. S., Scannapieco, M., Srivastava, D. and Wiwatwattana, N. Colorful XML: One hierarchy isn’t enough. In: Proceedings of ACM
SIGMOD International Conference on Management of Data (SIGMOD 2004), pages 251–262,
Paris,
June 13-18 2004. ACM Press New York, NY, USA. doi:https://doi.org/10.1145/1007568.1007598
Marinelli, P., Vitali,
F., and Zacchiroli, S. Towards the unification of formats for
overlapping markup. In: New Review of Hypermedia and Multimedia, 14(1): pages
57-94, 2008. doi:https://doi.org/10.1080/13614560802316145
Marcoux, Y. Graph characterization of overlap-only texmecs and other overlapping markup
formalisms. In: Proceedings of Extreme Markup Languages, Montréal, Québec,
2008
Pianta, E. and
Bentivogli., L. Annotating Discontinuous Structures in XML: the
Multiword Case. In: Proceedings of LREC 2004 Workshop on ”XML-based richly
annotated corpora”, pages 30–37, Lisbon, Portugal.
Poesio, M., Diewald, N.,
Stührenberg, M., Chamberlain, J., Jettka, D., Goecke, D. and Kruschwitz, U. Markup Infrastructure for the Anaphoric Bank, Part I: Supporting Web
Collaboration. In: Mehler, A., Kühnberger, K.-U., Lobin, H., Lüngen, H., Storrer,
A. and Witt, A. (eds.), Modelling, Learning and Processing of Text Technological Data
Structures, Dordrecht: Springer, Berlin, New York. To appear
Schonefeld, O. XCONCUR and XCONCUR-CL: A constraint-based approach for the validation of
concurrent markup. In: Rehm, G., Witt, A., Lemnitzer, L. (eds.), Datenstrukturen
für linguistische Ressourcen und ihre Anwendungen. Data Structures for Linguistic
Resources
and Applications. Proceedings of the Biennial GLDV Conference 2007, Tübingen, Germany,
2007.
Gunter Narr Verlag
Sperberg-McQueen, C. M., Huitfeldt, C. and Renear, A.. Meaning and
Interpretation of markup. Markup Languages – Theory & Practice,
2, pages 215-234, 2000. doi:https://doi.org/10.1162/109966200750363599
Sperberg-McQueen, C. M., Dubin, D., Huitfeldt, C. and Renear, A. Drawing inferences on the basis of markup. In: Proceedings of Extreme Markup
Languages, 2002
Sperberg-McQueen, C. M. and Huitfeldt, C. GODDAG: A Data Structure for
Overlapping Hierarchies. In: King, P. and Munson, E. V. (eds.), Proceedings of
the 5th International Workshop on the Principles of Digital Document Processing (PODDP
2000),
volume 2023 of Lecture Notes in Computer Science, pages 139–160. Springer, 2004
Sperberg-McQueen,
C. M. Rabbit/Duck grammars: a validation method for overlapping
structures. In: Proceedings of Extreme Markup Languages, Montréal, Québec,
2006
Sperberg-McQueen, C. M. and Huitfeldt, C. Markup Discontinued
Discontinuity in TexMecs, Goddag structures, and rabbit/duck grammars. Presented at Balisage: The Markup Conference 2008, Montréal, Canada, August 12 -
15, 2008. In: Proceedings of Balisage: The Markup Conference 2008. Balisage Series
on Markup Technologies, vol. 1 (2008). doi:https://doi.org/10.4242/BalisageVol1.Sperberg-McQueen01
Stührenberg, M.,
Goecke, D, Diewald, N., Cramer, I. and Mehler, A. Web-based annotation
of anaphoric relations and lexical chains. In: Proceedings of the Linguistic
Annotation Workshop (LAW), pages 140–147, Prague. Association for Computational Linguistics,
2007
Stührenberg, M.
and Goecke, D.SGF – An integrated model for multiple
annotations and its application in a linguistic domain. Presented at Balisage: The Markup Conference 2008, Montréal, Canada, August 12 -
15, 2008. In: Proceedings of Balisage: The Markup Conference 2008. Balisage Series
on Markup Technologies, vol. 1 (2008). doi:https://doi.org/10.4242/BalisageVol1.Stuehrenberg01
Thompson, H. S. and
D. McKelvie. Hyperlink semantics for standoff markup of read-only
documents. In: Proceedings of SGML Europe ’97: The next decade – Pushing the
Envelope, pages 227–229, Barcelona, 1997
Waltinger, U., Mehler, A.
Mehler, and Stührenberg, M. An Integrated Model of Lexical Chaining:
Application, Resources and its Format. Proceedings of the 9th Conference on
Natural Language Processing (KONVENS 2008)
Walsh, N., Milowski, A., and Thompson, H.
S. (2009). XProc: An XML Pipeline Language. W3C Candidate Recommendation 28 May 2009,
World
Wide Web Consortium.
Witt, A., Rehm, G., Hinrichs, E.,
Lehmberg, T. and Stegmann, J. SusTEInability of Linguistic Resources through Feature
Structures. In: Literary and Linguistic Computing, 24(3): pages 363-372, 2009. doi:https://doi.org/10.1093/llc/fqp024
Witt, A., Stührenberg, M.,
Goecke, D. and Metzing, D. Integrated Linguistic Annotation Models and
their Application in the Domain of Antecedent Detection. In: Mehler, A.,
Kühnberger, K.-U., Lobin, H., Lüngen, H., Storrer, A. and Witt, A. (eds.), Modelling,
Learning
and Processing of Text Technological Data Structures, Dordrecht: Springer, Berlin,
New York.
To appear
W3C XML Schema
Definition Language (XSD) 1.1 Part 1: Structures. W3C Working Draft, World Wide Web
Consortium, W3C Candidate Recommendation 30 April 2009. Online: http://www.w3.org/TR/2009/CR-xmlschema11-1-20090430/
