Fig. 6

Relationship annotation. When the user annotates a new relationship, the document’s content is blurred except for the mentions highlighted with different colors, which can be selected as subject, predicate, and object, respectively. The three steps to create a relationship are shown in the example examined. First, the object mention is selected from the menu (1); then, it is selected a predicate (2): by clicking on A, it is possible to manually type the predicate of the relationship, while by clicking on B it is possible to select a concept. In (3), the final relationship is represented: it comprises two mentions—the subject and the object and an ontological concept—the predicate. Each relationship element has a different color to make each element easily recognizable. The panel on the right allows the user to update and save the relationship