Interactive Narrative Experiences Research Articles

Evaluating User Engagement and Preference in Virtual Reality and Augmented Virtuality for Interactive Storytelling

Abstract Technologies like virtual reality (VR) and augmented virtuality (AV) based on head-mounted display (HMD) have made immersive interactive narrative experience possible. To investigate the differences between HMD VR and HMD AV for interactive storytelling, an app entitled the Extended Journey has been designed, developed and deployed on both VR headsets and optical see-through (OST) mixed reality (MR) headsets. Subsequently, a within-subjects design experiment with sixty participants was conducted to measure different factors of user experience in HMD VR and HMD AV conditions. Additionally, a between-subjects design experiment with 62 participants was conducted to evaluate narrative immersion and presence. Quantitative results from the experiments reveal that HMD VR narrative had statistically significantly better narrative immersion, presence, enjoyment and perceived affinity of computer-generated (CG) characters compared with HMD AV narrative in the context of galleries and museums. Based on Sundar's Modality-Agency-Interactivity-Navigability (MAIN) model, we proposed and validated that sense of being-there and interaction mediated the relationship between immersive media modality and narrative immersion as well as empathy. Qualitative data and behavioral tests showed that young people have a higher preference for HMD VR over HMD AV, but for specific use scenarios, there is still a certain possibility of choosing HMD AV due to security and space limitations. These findings have theoretical implications for the psychology of VR and AV, and practical applications for HMD-based immersive narrative in general.

Comparative Study of HMD-based Virtual and Augmented Realities for Immersive Museums: User Acceptance, Medium, and Learning

Technologies like Head Mounted Display (HMD)-based Virtual Reality (VR) and Augmented Reality (AR) have made HMD-based immersive museums possible. To investigate the user acceptance, medium, and interaction experience for HMD-based immersive museums, an app entitled The Extended Journey has been designed, developed, and deployed on both VR headsets and AR headsets. Subsequently, a between-subjects design experiment with 62 participants was conducted to measure the user experience and learning outcome in HMD VR and HMD AR conditions. Quantitative results revealed that HMD VR museums had statistically significantly better immersion and empathy compared to HMD AR museums. Qualitative data indicated HMD-based immersive museums were embraced by most young participants while HMD VR had better user acceptance than HMD AR for immersive museums. The interview also demonstrated that the advantage of the HMD-based immersive museum over the traditional online museum is not only the sensory immersion from the medium itself but also the interactive narrative experience that the HMD medium facilitates, especially the natural interaction with the CG characters and the environment in the story.

Playing with the Strings: Designing Puppitor as an Acting Interface for Digital Games

Interactive drama has focused on how to allow the player agency in influencing their experience through plot action. Interactive drama's preoccupation with changing plot structure bears little resemblance to theater's emphasis on character expression and dramatic play. Dramatic play allows the player to embody the character through actions, focusing on how characters express themselves and react rather than on how or even if that impacts the overarching sequence of events. In this paper, we present Puppitor, a system for character expression of emotion for interactive storytelling built using acting practice and fighting games as the foundation for its core design and describe its usage in conjunction with Ren'Py to facilitate a novel interactive narrative experience as a case study.

ReCapture: A VR interactive narrative experience concerning perspectives and self-reflection

This project presents a virtual reality (VR) Interactive Narrative aiming to leave users reflecting on the perspectives one chooses to view life through. The narrative is driven by interactions designed using the concept of procedural rhetoric, which explores how rules and mechanics in games can persuade people about an idea, and Shin’s cognitive model, which presents a dynamic view of immersion in VR. The persuasive nature of procedural rhetoric in combination with immersion techniques such as tangible interfaces and first-person elements of VR can effectively work together to immerse users into a compelling narrative experience with an intended emotional response output. The narrative is experienced through a young woman in a state between life and death, who wakes up as her subconscious-self in a limbo-like world consisting of core memories from her life, where the user is tasked with taking photos of the protagonist’s memories for her to come back to life. Users primarily interact with and are integrated into the narrative through a photography mechanic, as they have the agency to select ”perspective” filters to apply to the woman’s camera from which to view a core memory through, ultimately choosing which perspectives of her memories become permanent when she comes back to life.

A Modular Reinforcement Learning Framework for Interactive Narrative Planning

A key functionality provided by interactive narrative systems is narrative adaptation: tailoring story experiences in response to users’ actions and needs. We present a data-driven framework for dynamically tailoring events in interactive narratives using modular reinforcement learning. The framework involves decomposing an interactive narrative into multiple concurrent sub-problems, formalized as adaptable event sequences (AESs). Each AES is modeled as an independent Markov decision process (MDP). Policies for each MDP are induced using a corpus of user interaction data from an interactive narrative system with exploratory narrative adaptation policies. Rewards are computed based on users’ experiential outcomes. Conflicts between multiple policies are handled using arbitration procedures. In addition to introducing the framework, we describe a corpus of user interaction data from a testbed interactive narrative, CRYSTAL ISLAND, for inducing narrative adaptation policies. Empirical findings suggest that the framework can effectively shape users’ interactive narrative experiences.

Optimizing Player Experience in Interactive Narrative Planning: A Modular Reinforcement Learning Approach

Recent years have witnessed growing interest in data-driven approaches to interactive narrative planning and drama management. Reinforcement learning techniques show particular promise because they can automatically induce and refine models for tailoring game events by optimizing reward functions that explicitly encode interactive narrative experiences’ quality. Due to the inherently subjective nature of interactive narrative experience, designing effective reward functions is challenging. In this paper, we investigate the impacts of alternate formulations of reward in a reinforcement learning-based interactive narrative planner for the Crystal Island game environment. We formalize interactive narrative planning as a modular reinforcement-learning (MRL) problem. By decomposing interactive narrative planning into multiple independent sub-problems, MRL enables efficient induction of interactive narrative policies directly from a corpus of human players’ experience data. Empirical analyses suggest that interactive narrative policies induced with MRL are likely to yield better player outcomes than heuristic or baseline policies. Furthermore, we observe that MRL-based interactive narrative planners are robust to alternate reward discount parameterizations.

Unsupervised Text Classification for Natural Language Interactive Narratives

Natural language interactive narratives are a variant of traditional branching storylines where player actions are expressed in natural language rather than by selecting among choices. Previous efforts have handled the richness of natural language input using machine learning technologies for text classification, bootstrapping supervised machine learning approaches with human-in-the-loop data acquisition or by using expected player input as fake training data. This paper explores a third alternative, where unsupervised text classifiers are used to automatically route player input to the most appropriate storyline branch. We describe the Data-driven Interactive Narrative Engine (DINE), a web-based tool for authoring and deploying natural language interactive narratives. To compare the performance of different algorithms for unsupervised text classification, we collected thousands of user inputs from hundreds of crowdsourced participants playing 25 different scenarios, and hand-annotated them to create a gold-standard test set. Through comparative evaluations, we identified an unsupervised algorithm for narrative text classification that approaches the performance of supervised text classification algorithms. We discuss how this technology supports authors in the rapid creation and deployment of interactive narrative experiences, with authorial burdens similar to that of traditional branching storylines.

Automated Gameplay Generation from Declarative World Representations

An open area of research for AI in games is how to provide unique gameplay experiences that present specialized game content to users based on their preferences, in-game actions, or the system's goals. The area of procedural content generation (PCG) focuses on creating or modifying game worlds, assets, and mechanics to generate tailored or personalized game experiences. Similarly, the area of interactive narrative (IN) focuses on creating or modifying story worlds, events, and domains to generate tailored or personalized story experiences. In this paper we describe a game engine that utilizes a PCG pipeline to generate and control a range of gameplay experiences from an underlying IN experience management construct.

Towards Generating Narratives for the Real World

An immersive, interactive environment and the non-player characters populating it often play a key role in interactive narrative experiences. We posit that if a procedurally generated narrative is better able to reflect real-world attributes of the player's surroundings, then the experience would be more transportive for the player. With this comes the problem of generating believable narratives and characters for an open, complex, real world. Simulating such a society within the constraints of the real environment, and allowing for virtual characters to more accurately mimic human behavior could increase the believability of the agents. The interactions amongst these agents sharing their cultural views, biases, and histories based on their real-world geolocation could inform the study of audience modeling and machine enculturation, allowing computers to learn or reason about social norms in regions. Finally, we posit this research would afford better applications in the field of entertainment or computational social science.

Interactive Narrative Design beyond the Secret Art Status: A Method to Verify Design Conventions for Interactive Narrative

In recent years, game narrative has emerged as an area for novel game concepts and as a strategy to distinguish a particular title. However, innovation in this area comes primarily from indie companies and individual efforts by noted designers. There is a lack of trained specialists ready to produce interactive narrative experiences. Many existing practitioners are self-trained and often rely on intuition in their design practice. A key element missing from the effort towards a more sustained development and improved professional training is a set of design conventions that fulfill a role comparable to cinematic conventions like continuity editing or montage. Therefore, our research focuses on identifying, verifying and collecting such design strategies. We describe an empirical method to verify candidate design conventions through the evaluation of user reaction to A/B prototypes, which improves upon the trial-and-error process of old.

Scheherazade: Crowd-Powered Interactive Narrative Generation

Interactive narrative is a form of storytelling in which users affect a dramatic storyline through actions by assuming the role of characters in a virtual world.This extended abstract outlines the Scheherazade-IF system, which uses crowdsourcing and artificial intelligence to automatically construct text-based interactive narrative experiences.

Lessons on Using Computationally Generated Influence for Shaping Narrative Experiences

In this paper, we present computational models for generating influence that allow story managers to shape players' decisions in interactive narrative experiences. Our approach uses concepts from social psychology, discourse analysis, and natural language generation. We describe an abstract formalism to operationalize tools of social psychological influence described by Cialdini (Influence: The Psychology of Persuasion, New York, NY, USA: Harper-Collins, 1998) and evaluate two example implementations that enable a storytelling system to generate influence on the fly (with varying degrees of success), thereby adapting stories to realize goals specified by authors. These implementations are used in an interactive story where influence is generated dynamically as players' experiences unfold. We present the results of a user study to characterize the effectiveness of these models. Results did not indicate the presence of any significant differences in players' sense of control over the story with, or without, the use of influence. Further, the use of influence resulted in a set of stories experienced by players that more closely matched the author's goals.

Virtual Reality as a Tool for Delivering PTSD Exposure Therapy and Stress Resilience Training

The incidence of post-traumatic stress disorder (PTSD) in returning Operation Enduring Freedom and Operation Iraqi Freedom military personnel has created a significant behavioral health care challenge. One emerging form of treatment for combat-related PTSD that has shown promise involves the delivery of exposure therapy using immersive virtual reality (VR). Initial outcomes from open clinical trials have been positive, and fully randomized controlled trials are currently in progress. Inspired by the initial success of our research using VR to emotionally engage and successfully treat persons undergoing exposure therapy for PTSD, we have developed a similar VR-based approach to deliver resilience training prior to an initial deployment. The STress Resilience In Virtual Environments (STRIVE) project aims to create a set of combat simulations (derived from our existing virtual Iraq/Afghanistan PTSD exposure therapy system) that are part of a multiepisode interactive narrative experience. Users can be immersed within challenging virtual combat contexts and interact with virtual characters as part of an experiential approach for learning emotional coping strategies believed to enhance stress resilience. This article describes the development and evaluation of the virtual Iraq/Afghanistan exposure therapy system and then details its current transition into the STRIVE tool for predeployment stress resilience training.

Experiencing interactive narrative: A qualitative analysis of Façade

The topic of interactive narrative has been under research for many years. While there is research exploring the development of new algorithms that enable and enhance interactive narratives, few research projects focused on the question of how users interpret and experience an interactive narrative. In this paper we specifically focus on a single user interactive narrative experience since most work within this area focused on technological advancement and less on measurements of participants’ experiences. Taking this angle, we aim to report on an in-depth qualitative content analysis study, specifically analyzing users’ interpretations, emotions, and behavioral responses to an interactive narrative called Façade. We analyzed user data, including interviews and action logs, which include dialog uttered between participants and characters that inhabit Façade. Results from this analysis are discussed in the paper along with the methodology used and its limitations. These findings uncover several useful lessons that can help guide the design of future single user interactive narratives similar to Façade.

Robust and Authorable Multiplayer Storytelling Experiences

Interactive narrative systems attempt to tell stories to players capable of changing the direction and/or outcome of the story. Despite the growing importance of multiplayer social experiences in games, little research has focused on multiplayer interactive narrative experiences. We performed a preliminary study to determine how human directors design and execute multiplayer interactive story experiences in online and real world environments. Based on our observations, we developed the Multiplayer Storytelling Engine that manages a story world at the individual and group levels. Our flexible story representation enables human authors to naturally model multiplayer narrative experiences. An intelligent execution algorithm detects when the author's story representation fails to account for player behaviors and automatically generates a branch to restore the story to the authors' original intent, thus balancing authorability against robust multiplayer execution.

The Fantastic Flying Books of Morris Lessmore by W. Joyce

Joyce, William. The Fantastic Flying Books of Morris Lessmore. Shreveport, LA: Moonbot Books, 2011. iPad app. It seems strange that a story that expresses such love towards books as physical objects was first produced as an award-winning animated short film, and then adapted into an “interactive narrative experience” for the iPad. The protagonist, Morris Lessmore, is transported via hurricane to another land where he encounters a young woman held aloft by a flock of anthropomorphized flying books. One book leads him to a house full of more books, where he ends up living. He takes care of the books, and lends them to drab, black-and-white people who bloom into full colour (à la Wizard of Oz) as soon as they receive their reading material. Finally, as an old man, he is whisked away by the books, and the book that he wrote is used to draw a young girl into the house to take over his role as caretaker.It is usually the fate of new media to be unfavourably compared to more established media forms, but in this case, Morris Lessmore also suffers from being an adaptation rather than an original work. This iPad version seems uncomfortably caught between the fluidity and liveliness of the original animated film and the sequential narrative of a traditional picture book. Like a video game adaptation of a major motion picture in which the player re-enacts a simple replay of the movie plot, many of the interactive features of this book app seem contrived, acting as tacked-on gimmicks rather than being truly integrated with the story as a unique experience. However, that does not mean that the narrative experience is entirely without merit. The animation (taken directly from the film) looks amazing on the iPad’s vibrant screen, and finding the hidden “Easter eggs” on each page is quite entertaining for all ages. Moonbot Studios also gets extra credit for its inventive use of the iPad’s touch interface - readers will enjoy swiping, coloring, dragging, and even playing the piano on the screen, even if these activities are sometimes tangential to the narrative itself. Despite its shortcomings, Morris Lessmore stands out as exceptional in comparison to other picture book apps currently available for the iPad. As a final incentive, it is very reasonably priced; for only $4.99 at the iTunes Store, the app is much less than your average print picture book (although there’s not much chance of finding it at your local library).Recommended: 3 out of 4 starsReviewer: Dale StorieDale Storie is Public Services Librarian at the John W. Scott Health Sciences Library at the University of Alberta. He has a BA in English, and has also worked in a public library as a children's programming coordinator, where he was involved with story times, puppet shows, and book talks.

Warriors’ Journey: a path to healing through narrative exploration

The Warriors’ Journey is an interactive narrative experience that is part of the online, virtual world healing space of the Coming Home Project (www.cominghomecenter.org) at the University of Southern California’s Institute for Creative Technologies. This project is exploring new ways to reach veterans who are returning from recent conflicts and who often have mental health issues or difficulty fitting back into their home communities. We are looking at the affordances of online 3D virtual worlds to address some of the issues that may prevent or deter veterans from getting the help they need. We are exploring the use of specific therapies within the virtual world space, as well as social and enrichment activities designed around the needs of this group. The Warriors’ Journey is one such activity that engages participants in stories to emphasize and reinforce common ideals of honorable warriors throughout history. After experiencing these stories, participants are then encouraged to construct their own warior’s story within the Coming Home space. It is hoped that such activities may help contribute to a more positive sense of self-esteem, a restructured life narrative, and a feeling of control over the stresses incurred during their service to their country.

Interaction, narrative, and drama

Interactive narratives have been used in a variety of applications, including video games, educational games, and training simulations. Maintaining engagement within such environments is an important problem, because it affects entertainment, motivation, and presence. Performance arts theorists have discussed and formalized many techniques that increase engagement and enhance dramatic content of art productions. While constructing a narrative manually, using these techniques, is acceptable for linear media, using this approach for interactive environments results in inflexible experiences due to the unpredictability of users’ actions. Few researchers attempted to develop adaptive interactive narrative experiences. However, developing a quality interactive experience is largely an art process, and many of these adaptive techniques do not encode artistic principles. This paper presents a new interactive narrative architecture designed using a set of dramatic techniques that have been formulated based on several years of training in film and theatre.