Pointing relations

Pointing relations are ahierarchical edges between any two annotation node elements, that is between any combination of tok, mark or struct. Unlike hierarchical edges, pointing relations do not express 'dominance' semantics, meaning that the source of the edge is not understood to 'consist of' the target of the edge. The edge merely marks a relationship between two nodes. For this reason, pointing relations are useful in expressing such links as coreference (e.g. a link between anaphor and antecedent) and syntactic dependencies. Pointing relations are represented using rel elements in rel files, and obey the definition in paula_rel.dtd (see DTDs). The following example illustrates rel edges between tokens defined in the file mycorpus.doc1.tok.xml, but the sources and targets of the edges can also be any struct or mark within a document.

Pointing relations between token nodes to annotate dependencies of type "dep"

<?xml version="1.0" standalone="no"?>
<!DOCTYPE paula SYSTEM "paula_rel.dtd">

<paula version="1.1">

<header paula_id="mycorpus.doc1_dep"/>

<relList xmlns:xlink="http://www.w3.org/1999/xlink" type="dep" 
xml:base="mycorpus.doc1.tok.xml">
    <!-- I - 've -->
    <rel id="rel_1" xlink:href="#tok_1" target="#tok_2"/> 
    <!-- 've - picked -->
    <rel id="rel_2" xlink:href="#tok_3" target="#tok_2"/> 
    <!-- the - kids -->
    <rel id="rel_3" xlink:href="#tok_4" target="#tok_5"/> 
    <!-- picked - kids -->
    <rel id="rel_4" xlink:href="#tok_5" target="#tok_3"/> 
    <!-- picked - up -->
    <rel id="rel_5" xlink:href="#tok_6" target="#tok_3"/> 
</relList>

</paula>

The rel file only defines the edges and the @type of the relList, in this case "dep". To add an annotation to these edges, for example grammatical functions, a feat file is used, as in the following example:

Annotating the grammatical function "func" for dependency pointing relations

<?xml version="1.0" standalone="no"?>

<!DOCTYPE paula SYSTEM "paula_feat.dtd">
<paula version="1.1">

<header paula_id="mycorpus.doc1_dep_func"/>

<featList xmlns:xlink="http://www.w3.org/1999/xlink" type="func" 
xml:base="mycorpus.doc1.dep.xml">
    <feat xlink:href="#rel_1" value="SBJ"/><!-- I - 've -->
    <feat xlink:href="#rel_2" value="VC"/><!-- 've picked -->
    <feat xlink:href="#rel_3" value="NMOD"/><!-- the - kids -->
    <feat xlink:href="#rel_4" value="OBJ"/><!-- picked - kids -->
    <feat xlink:href="#rel_5" value="PRT"/><!-- picked - up -->
</featList>

</paula>

Each feat element points to a rel element in the pointing relation file and gives the annotation value in its @value attribute. The name of the annotation, "func", is determined in the @type attribute of the featList.

Just as with markables, it is also possible to specify multiple annotations for the same pointing relations in one XML document using multiFeat files (see multiFeats for details).