Perceptual Experience Managemen

In strong story experience management there is a tension between player autonomy and authorial control. Autonomy is a player's ability to choose from a full range of actions a orded by the environment and make meaningful change to the story world. Control is an author's ability to impose specific narrative structures in the interactive experience. In automated experience managers, authors impose narrative structures by specifying constraints on the sequences of story events and world states. In these systems, the tension between player autonomy and authorial control arises when a player's action prevents an authorial constraint from holding. When a player acts on an opportunity to break an authorial constraint, there are two options available to an interactive narrative system that preserve both player autonomy and authorial control. The first, called intervention, modifies the outcome of the player's action so it no longer reverses the authorial constraint. The second method, called accommodation, selects a new story that incorporates the player's action and still conforms to the author's constraints. However, neither of these alternatives are ideal. If the system alters the behavior of a player's action, the player may notice an inconsistency between different similar contexts in which the action is performed. Alternatively, a second story that both incorporates the player's action and adheres to the author's constraints does not always exist.;This document presents an automated strong story experience manager that mitigates drawbacks of both approaches by utilizing a model of player knowledge. First, the experience manager ensures interventions are consistent across game contexts by constraining the space of interventions to exclude those that contradict what the player has previously observed. The experience manager also widens the space of possible accommodations to include alternate possible world histories that are consistent with past player observations. Together, these two components shift the story world between possible worlds consistent with player observations to better maintain author constraints. This process is called perceptual experience management. The framework is implemented in a novel hybrid experience manager and game engine called the General Mediation Engine (GME). GME is specially suited for the framework because it merges the declarative methodology of automated strong story experience managers with procedural commercial game engines by utilizing a content generation pipeline to dynamically assemble and revise game content based on the experience manager's underlying symbolic state. Because GME's state representation and update mechanics are embedded in the experience manager's representation, the game world the player interacts with dynamically reconfigures whenever the experience management framework modifies the underlying world state or action transitions.;Finally, this document presents a series of structural and human subject evaluations of the experience manager. It is hypothesized that the experience manager will expand a larger number of branches consistent with author constraints while avoiding branches where players notice modifications of the story world state and mechanics. First, GME is used to evaluate whether the experience manager expands more branches consistent with author constraints by comparing interactive narrative trees produced by perceptual experience management against trees produced by a baseline method. Next, a series of three human subjects experiments are presented that show players notice inconsistencies produced by perceptual experience management when the modifications are not constrained by a model of player knowledge. Together, these evaluations provide evidence that perceptual experience management better mediates the tension between player autonomy and authorial control by expanding the number of branches in interactive narrative trees consistent with author constraints while retaining the player's access to their full range of choice options. This is achieved by maneuvering players between possible world models consistent with their story world observations.