From nn to Curveship

This is the fourth in a series of posts about my interactive fiction system, Curveship.

I was recently asked to elaborate on the difference between nn (the research system I developed during my dissertation work at the University of Pennsylvania) and Curveship.

The most important difference is that nn is a research system that I used for making some advances related to computer science, computational linguistics, and narratology. The system was developed to prove certain points; it was used only by yours truly to implement narrative and text generation ideas and to run demos.

It worked pretty well for this. Using nn, I developed a new representation for the order of actions, one that can be used flexibly in text generation. I put together a string-with-slots representation used in templates, one that is much less cumbersome to use than a general abstract syntax representation. And I worked out how a focalizer world (now called a “concept”) can model an actor’s theory about the “real” or “actual” world that is central to an interactive fiction.

That’s not to say that you’d want to pick up this system, though, and start writing games in it. While nn in 2007 had all the basic components of an IF system (a parser, the ability to save an restore games, the ability to model a world), they were not all ready for prime time, because my development work was focused on trying to answer particular research questions.

So, I took the nn code and began working on a new project, Curveship. I wanted to release a system that was developed with other IF authors, other AI researchers, and other teachers of narrative theory and electronic literature in mind. Curveship is getting close to being this system – within a few months, I hope, I will get it to that point, with the help of a group of people, the Curveship crew, who are testing and commenting on pre-release versions.

Concretely, there are three main sorts of differences. First, bugs in nn that my limited use of the system didn’t expose have been fixed – and more will be. Second, there are improved capabilities that didn’t relate to my research goals, but which are important to IF authors. These range from better parsing and clarification (disambiguation) to better ways of formatting text to better capabilities for simulating physical aspects of the world. Finally, I have impeoved the interface, which includes changing the names of some components of the system. What used to be a “plan for narrating” is now “spin.” What I called “existents” (a perfectly nice but abstruse term from narratology) are now, more simply, called “items.” To avoid confusion, I even changed the name of the “Narrator” module, because “narrator” is a narrative function and a parameter that can be set within the system. This module is now called the “Teller.” There have been other name changes and a great deal of refactoring, some writing of docstrings, and other improvements to make the Curveship code more understandable and manipulable to those who want to get into it. The way string-with-slots templates are written has changed, too, as has the way items and actions are created.

The discussion of reply structures, focalizer worlds, and similar aspects of the system in previous publications (such as my dissertation) remains largely applicable to Curveship. But because Curveship is being developed with an eye toward a new group of author/programmers, researchers, and teachers, there have been many changes beyond the parts of nn that implement those core research contributions. Even some of publications and talks about Curveship from recent months have names for components that are now different and mention the old style string-with-slots formalism. That’s one of the reasons I’ve started in on this series of posts.