nzilbb.ag

This is an Annotation Graph API for linguistic annotations.

Annotation Graphs are a data structure conceived by Steven Bird and Mark Liberman:

• (http://lanl.arxiv.org/abs/cs/9907003)
• (http://xxx.lanl.gov/PS_cache/cs/pdf/9903/9903003v1.pdf)

The structure is designed to be a tool-independent way of representing annotated linguistic data, and essentially defines an Annotation Graph as a directed acyclic graph where:

• nodes are ‘anchors’ that represent a point in time (in seconds) or a point in a text (in characters) (although the time/character offset label is optional), and
• edges are ‘annotations’ which have a ‘label’ (the content of the annotation) and a ‘type’ (the kind of annotation, analogous with an ‘tier’ or ‘layer’)

This particular implementation, which is used for LaBB-CAT, developed by the NZILBB, includes extra features that allow tier hierarchies and parent/child constraints to be defined. More details on extra features are available in http://dx.doi.org/10.1016/j.csl.2017.01.004

More API documentation is available here