They collected computer-generated story arcs for nearly 2,000 works of fiction, classifying each into one of six core types of narratives (based on what happens to the protagonist):
1. Rags to Riches (rise)
2. Riches to Rags (fall)
3. Man in a Hole (fall then rise)
4. Icarus (rise then fall)
5. Cinderella (rise then fall then rise)
6. Oedipus (fall then rise then fall)
Their focus was on the emotional trajectory of a story, not merely its plot.