GraPAT (Graph-based Potsdam Annotation Tool, [Sonntag and Stede 2014], http://www.lrec-conf.org/proceedings/lrec2014/pdf/824_Paper.pdf) is web-based and provides annotators with a natural visualisation of their annotations and thus supports the intuitions of annotators to follow graph-based annotation schemes.
Supported annotations are
- Relation-based sentiment
- Argumentation structure
The tool provides a graph structure annotation on top of text. Certain parts of the text can be connected to nodes in the graph, and those nodes can be connected with relations of the relevant annotation scheme. Edges also have attributes to describe them.