Propp's Morphology of the Folk Tale as a Grammar for Generation

The semi-formal analysis of Russian folk tales carried out by Vladimir Propp has often been used as theoretical background for the automated generation of stories. Its rigour and its exhaustive description of the constituent elements of Russian folk tales, and the enumeration of the patterns they follow, have acted as inspiration for several story generation systems, both sequential and interactive. Yet most of these efforts have attempted to generalize Propp’s account to types of stories beyond the corpus that it arose from. In the process, a number of the valuable intuitions present in the original work are lost. The present paper revisits Propp’s morphology to build a system that generates instances of Russian folk tales. Propp’s view of the folk tale as a rigid sequence of character functions is employed as a plot driver. Unification is used to incrementally build a conceptual representation of discourse by adding to an ongoing draft story actions that instantiate the character functions. Story actions are defined by pre and post conditions on the state of the plot to account for the causal relations crucial to narrative. The potential of the resulting system for providing a generic story generation system is discussed and possible lines of future work are discussed.