Steps Towards a Formal Ontology of Narratives Based on Narratology Carlo Meghini, Valentina Bartalesi, Daniele Metilli {meghini,bartalesi,metilli}@isti.cnr.it ISTI-CNR, Pisa

A Digital Library Problem Limitation of the informative services offered to the user A case in point: Europeana Approach: to introduce a new entity in DLs that help improving the search functionality of DL and more

The problem The development of a formal ontology to represent simple narratives that can be used in digital libraries to support: all users in better accessing the content of the digital library indexers and scholars in creating narratives, and in composing, merging and comparing them.

Narratology Background Aristotle Russian formalists Post-structuralists Computational narratology

Conceptualization Formal computable representation of narrative, as derived from the narratology background A narrative consists of three main elements: the fabula, directly representing the fabula as defined by the Russian formalism, i.e., the sequence of the events that composes the story in chronological order; one or more texts that narrate the fabula, that we call narrations and that correspond to the Bal’s definition of presentation; a reference function that connects the narrations to the fabula and allows us to derive the syuzhet (or plot) as defined by the Russian formalism.

Fabula The fabula is built on top of eventsIn a fabula, events are connected to each other by three kinds of relations: a mereological relation, relating events to other events that include them as parts, e.g., the birth of Dante Alighieri is part of the life of Dante; a temporal occurrence relation, associating each event with a time interval during which the event occurs. We formalize this relations between events using the Allen’s temporal logic; a causal dependency relation, relating events that in normal discourse are predicated to have a cause-effect relation in the narrator’s opinion, e.g., the eruption of the Vesuvius caused the destruction of Pompeii.

Narration Each narration of a fabula consists of one or more narrators and a text, which is authored by the narrator(s) and constitutes the narration. We focus on the only aspect that is functional to our model of narrative, namely textual content that is the language expression that constitutes the content of a piece of text.

Reference Function The reference function connects each portion of text that narrates an event to the narrated event In order to model a reference we need to identify textual units, which we call narrative fragments (or simply fragments), each of which narrates a single event the reference function allows deriving the plot of the narrative. By visiting the text of the narration in its natural order, it is possible to access the narrative fragments and, via these, the events in the fabula, in the order established by the narrator

Experimental Implementation CIDOC-CRM and CRMInf

Biography of Dante Development of a semi-automatic tool to populate the ontology The tool automatically populates the top classes of our ontology by looking up the Wikidata knowledge base  mapping between Wikidata and CRM classes At the moment, automatic visualization of narratives on a timeline

Experimental Implementation

Experimental Implementation The text written by the narrator  E73 Information Object Chapters, paragraphs  E73 Information Object Fragment  ExpressionFragment of FRBRoo Narrator  E21 Person

Experimental Implemetation

Experimental Implementation To represent the reference function of a narrator we have used CRMinf

Open issues What is a narrative as a whole What is a fabula as a whole What is a story structure, or story grammar, or story template? description culture of a community abstract from the past (myhts, Propp’s functions) shape the future (avoid mistakes) resemble the laws sought by historians evolve

Thank you