Machines that write stories, emotion included

Machines that write stories, emotion included

February 18, 2007

By Katie Haegele

There are lots of different ways to tell a story. Think of the few you might have enjoyed just this week: novels, movies, TV dramas and sit-coms.

But it could be that there are certain underpinnings to the act of story-creation itself, and computer systems that generate stories might give us a better understanding of the nature of creativity.

MEXICA, created by Rafael Pérez y Pérez at Autonomous Metropolitan University in México City, is a new artificial intelligence-based system that generates original stories about the ancient inhabitants of that city, known as the Mexicas. Given basic details, MEXICA produces very short stories about the love and violence between knights, kings, and princesses. Computerized storytellers similar to this one have been in existence since the 1970s.

In a paper introducing his system, Pérez y Pérez writes that emotions are an integral part of the creative process, but that emotion does not play a fundamental role in many computer models of creativity. MEXICA does so by tagging characters with their emotional connection to each other, represented along a continuum between love and hate, and using the connections to drive plot development.

MEXICA also uses tension and emotion to evaluate the "interestingness" of its output. In an online survey that asked readers to evaluate stories generated by MEXICA, other systems, and one written by a person for coherence, structure, content, and feeling of suspense, a MEXICA story ranked highest.

In his paper, Pérez y Pérez writes that the sucess of MEXICA suggests that “creative products...are not necessarily exclusively the result of an explicit goal-oriented activity.” In a sense, then, the system works like the author who says she knows her characters but not how they’ll react to what happens to them until she begins writing.

"MEXICA tries to function like a creative writer: It presents a model of creating interesting, surprising incidents and then smoothly bringing the story from one to another. So in addition to being a good story-generating system, it makes an argument about how creativity happens," says Nick Montfort, a PhD student at the University of Pennsylvania and the author of Twisty Little Passages: An Approach to Interactive Fiction. Montfort heard Pérez y Pérez talk about MEXICA at an artificial intelligence workshop in July and calls it impressive.

Asked if writers are resistant to the idea of a computer doing what they do, Pérez y Pérez says he meets people "who are very enthusiastic about computational creativity and others who are very afraid of it."

"We human beings always have employed tools to help us to conceptualize new ideas," said Pérez y Pérez, who has composed music and written his own short fiction. "For example, think of how an architect employs blueprints and scale models to build a tower. Those are external tools that help the creative people to see and better understand their own ideas. Computers are the same: they are tools that help us visualize complex systems.

"We are far away from being able to create a system capable of making literature like we human beings do. However, if we can build a system that generates adequate short stories, that means that we have understood better how the creative process works."

go back