SCIENCE

SEATTLE, WA -- Journalists beware. In just a few years' time, a piece of software might make you obsolete. It is already capable of writing convincing fairy tales. Newspaper articles may be next, the American Association of Artificial Intelligence heard last week. The intelligent system, called Author, was developed by Charles Callaway and James Lester at North Carolina State University in Raleigh to help children get over literacy problems. By changing details about characters, props and plot, it generated new takes on fairy tales. The software can already tell a mean version of Little Red Riding Hood. But, given a different knowledge base, says Callaway, it could just as easily write newspaper stories, short stories and movie scripts. For now, Author lacks a decent "front-end" user interface, he says, so feeding it the facts is extremely labour-intensive. "It involves several orders of magnitude more effort than writing by hand." But the development of a "narrative planner" will ease this. Eventually, Callaway sees programs like his being married to systems that extract information from text. This would make it possible to dispatch automated roving news hounds to scan news wires or government papers for the bare bones of a story. Such AI systems, known as automated summarisers, already exist in basic form. Daniel Marcu at the Information Sciences Institute of the University of Southern California, in Marina del Rey, has done extensive work in this area. "I take any text and try to understand its structure and the arguments underlying it," he says. From this, software generates short-sentenced summaries. But Author is the best by far at generating readable prose, says Marcu. Although people have worked on this for more than twenty years, much of the research has focused on specific problems and usually only produces stories a couple of paragraphs long. Callaway has taken a broader approach, generating stories a number of pages long. His is the only program that can generate dialogue between characters. To write the story, Author is given a story plan consisting of the characters, scenes, props and the order of events. This information is entered as single proposition sentences, such as "wolf eats grandmother", detailing relationships between characters and concepts and the order in which events occur. Using the plot outline to order events, Author then strings these facts together into sentence-like groups and applies a series of rules that turn them into grammatically correct sentences. To make them readable, a number of techniques are applied to avoid sentences like: "Grandmother knew that Grandmother had asked Grandmother's daughter to send some cakes to Grandmother." Marcu believes it will be a while yet before Author can write hot news automatically, not least because it will have to find a way to tell fact from fiction. "There's no need for journalists to worry just yet," he concedes. ---------- Duncan Graham-Rowe reports from Seattle on this week's International Joint Conference on Artificial Intelligence. New Scientist issue: 11 August 2001 www.newscientist.com