Stefan Rank | Drexel University (original) (raw)

Papers by Stefan Rank

Proceedings of the 13th International Conference on Advances in Computer Entertainment Technology

Virtual reality (VR) enables unusual experiences, including the physically impossible, in an imme... more Virtual reality (VR) enables unusual experiences, including the physically impossible, in an immersive environment. As new media such as VR are developed, designers tend to remediate aspects from previous media, but not every aspect fits. Several areas in VR design warrant scientific investigation in that regard. This paper specifically addresses transitioning between environments: when transitioning in a virtual world, will camera movements made simultaneously and in sync with movements from the user produce a preferred scene transition experience compared to virtual camera movement that is less directly coupled? We report on a within-subject experiment where participants were tasked with transitioning between different environments. One set of transitions required the full physical motion of the user to complete, for the other set completing the transition was triggered after a part of the physical movement was performed up to a threshold. Results showed a clear preference for the second variant and thus for less control over the virtual camera.

Previous research on understanding the effects of computer gameplay showed a shift from negative ... more Previous research on understanding the effects of computer gameplay showed a shift from negative behavioral consequences to positive cognitive development across multiple age groups. A positive correlation exists between spatial skills and indications of success in science, technology, engineering, and mathematics fields. Game-based regimens explored training cognition and focus on spatial abilities as many post-secondary students with poor spatial skills can be place at a disadvantage in introductory courses. While the results of game-based studies suggested the potential of games, there were limitations to the studies conducted. Research examining effects from gameplay often compared across different genres, levels of graphical fidelity, input methods, and other variables. Which aspects of gameplay have an impact on the positive consequences is an open question. We focused on the role of spatial involvement, expressed as different control schemes, and its impact on training mental...

Non-player characters (NPCs) in video games have very little information about the player's c... more Non-player characters (NPCs) in video games have very little information about the player's current state. This disconnect leads to less than ideal interactions between the human and the computer. Measurements of a human's physiological state have been used to drive a wide range of software interactions, such as biofeedback applications. The usage of physiological data in games has been very limited, mainly to adjustments in difficulty based on stress levels. However, research with virtual agents has shown how useful physiological data can be in human-computer interaction. Based on these findings, this thesis assesses the usefulness of physiological signals for the interaction with NPCs. Measurements of skin conductance on the fingers and facial muscle tension serves as a means to estimate the player's emotional state at any given time. This data is then used to adjust the behavior of non-player characters in so far as their dialogue acknowledges the player's emotion. An experimental evaluation of the developed system showed that using a combination of electromyography and electrodermal activity to estimate human emotion affords non-player characters with more information about the player, demonstrating the viability of the approach. In the small sample of the evaulation, there was no significant difference for a questionnaire measure of rapport with the NPCs. However, the qualitative feedback in the questionnaires showed a clear difference in the perception of the system's use of physiological information. How this information can be used most effectively by non-player characters should be explored further in future research.

Basing artificial emotion on process and resource management The Austrian Research Institute for ... more Basing artificial emotion on process and resource management The Austrian Research Institute for Artificial Intelligence is supported by the

Simulated dramatic story-worlds need to be populated with situated software agents that act in a ... more Simulated dramatic story-worlds need to be populated with situated software agents that act in a dramatically believable way. In order to provide flexible roleplayers, agent architectures should limit the required external macro-level control. We present work on an architecture that exploits social embedding and concepts from appraisal theories of emotion to achieve the enactment of simple cliche ́ plots. The interplay of motivational constructs and the subjective evaluative inter-pretation of changes in an agent’s environment provide for the causal and emotional connections that can lead to the unfolding of a story.

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Humor is an essential part of storytelling, but it has not been studied in the field of interacti... more Humor is an essential part of storytelling, but it has not been studied in the field of interactive emergent narrative. We begin with an overview of various theories of humor and use them to examine examples of humor within the digital media field. This juxtaposition aims to bring together concepts from both fields in order to find a feasible direction. We hope to contribute a framework of humor that can be used in the near future for an interactive emergent narrative project. Our conceptualization of humor frames it in terms of "pleasant surprises" which enable players and other emergent AI actors to stretch the boundaries between plot and discourse.

Advances in Visual Computing, 2021

As the sophistication of video games increases, flaws in certain aspects of games, such as commun... more As the sophistication of video games increases, flaws in certain aspects of games, such as communicating with non-player characters (NPCs), become more apparent. NPCs have limited information about the players, but they should ideally react to the players’ emotional state. We propose an experiment to test the feasibility of using physiological data as an estimate of emotional states to improve this aspect of interaction between players and NPCs. Leveraging advances in biofeedback applications, the proposed setup uses galvanic skin response and electromyography for emotion estimation in an action role-playing game built in Unity. Players navigate through a post-apocalyptic setting as their physiological data is recorded during significant, in-game, events. We present the within-subjects experimental design in which this data will be utilized to influence the dialogue behaviors of NPCs in the game and the resulting effect on rapport with the characters will be tested.

Understanding Complex Systems, 2016

Computer-mediated communication between humans is at the center of the formation of collective em... more Computer-mediated communication between humans is at the center of the formation of collective emotions on the Internet. This chapter presents how interactive affective systems can be applied in order to study the role of emotion in online communication at the micro-scale, i.e. between individual users or between users and artificial communication partners. Specifically, we report on the effect of a simulated conversational partner’s affective profile, the use of fine-grained communication scenarios and social interaction context on changes in emotional states and expressed affect of users as well as their communication patterns. Based on these findings, we propose applications for such systems focused on supporting different e-communities with real-time information and discuss ethical implications of such systems.

Lecture Notes in Computer Science, 2016

Non-player characters (NPCs) in video games have very little information about the player’s curre... more Non-player characters (NPCs) in video games have very little information about the player’s current state. The usage of physiological data in games has been very limited, mainly to adjustments in difficulty based on stress levels. We assess the usefulness of physiological signals for rapport in interactions with story characters in a small role-playing game, Exit53. Measurements of electrodermal activity and facial muscle tension serves as estimate of player affect which is used to adjust the behavior of NPCs in so far as their dialogue acknowledges the player’s emotion. An experimental evaluation of the developed system demonstrates the viability of the approach and qualitative data shows a clear difference in the perception of the system’s use of physiological information.

Proceedings of the 2016 Annual Symposium on Computer-Human Interaction in Play Companion Extended Abstracts, 2016

Proceedings of the 2016 Annual Symposium on Computer-Human Interaction in Play Companion Extended Abstracts - CHI PLAY Companion '16, 2016

What aspects of gameplay have a positive impact on cognitive development? This work-in-progress f... more What aspects of gameplay have a positive impact on cognitive development? This work-in-progress focuses on the role of spatial involvement via different control schemes by implementing a training regimen through Minecraft for mental rotation in order to understand the impact of aspects of involvement on the training outcome. A proven engaging training experience was recreated, making training mental rotation more accessible and extending it using digital media. We compare different levels of spatial involvement in a pilot study to understand factors of the experience's impact as a first step towards an improved understanding of relevant aspects of digital games for training.

Applied Artificial Intelligence, Jul 1, 2014

Autonomous characters in interactive storytelling can be supported by using affective agent archi... more Autonomous characters in interactive storytelling can be supported by using affective agent architectures. The configuration of most current tools for controlling agents is, however, implementation specific and not tailored to the needs of authors. Based on literature review, a questionnaire evaluation of authors’ preferences for character creation, and a case study of an author’s conceptualization of this process, we investigate the different methods of configuration available in current agent architectures, reviewing discrepancies and matches. Given these relations, promising approaches to configuration are identified, based on initial inner states, “global” parameters of characters, libraries of stock characters, and selections of backstory experiences.

Proceedings of the 2016 CHI Conference Extended Abstracts on Human Factors in Computing Systems - CHI EA '16, 2016

Previous research demonstrates a shift from negative behavioral consequences to positive cognitiv... more Previous research demonstrates a shift from negative behavioral consequences to positive cognitive development in understanding the effects of computer gameplay across multiple age groups. However, there are still questions about which aspects of gameplay have an impact on those positive consequences. This work-in-progress focuses on the role of spatial involvement via different control schemes by implementing a training regimen through Minecraft for mental rotation in order to understand the impact of aspects of involvement on the training outcome. The project utilizes Minecraft to recreate a proven engaging experience for players, making training mental rotation more accessible. Comparing different levels of spatial involvement will be used to understand factors of the experience's impact. Further, the work extends game training endeavors in psychology using digital media. A target outcome is an improved understanding of what aspects of digital games are relevant for successful training applications.

Seventh Intelligent Narrative Technologies Workshop, Oct 23, 2014

Film cinematography has been developed and applied for more than a century to involve and engage ... more Film cinematography has been developed and applied for more than a century to involve and engage the viewer in visual storytelling. Interactive storytelling games can benefit from these cinematic conventions to enhance visual experience. However, even conversation scenes in games are highly dynamic, and pre-authoring camera parameters using cinematography principles is often insufficient. This paper proposes an automatic Visual Director System focused on dynamic conversation scenes involving three characters and reports on work in progress on a prototype applied to the recreation of a movie scene. Based on principles of cinematography and the study of film scenes, cinematic conventions for triadic conversations are encoded modularly as an artificial intelligence game component that selects suitable shots for dynamic scenes.

2015 International Conference on Affective Computing and Intelligent Interaction (ACII), 2015

We demonstrate PhysSigTK, a physiological signals toolkit for making low-cost hardware accessible... more We demonstrate PhysSigTK, a physiological signals toolkit for making low-cost hardware accessible in the Unity3D game development environment so that designers of affective games can experiment with how engagement can be captured in their games. Rather than proposing a context-free way of measuring engagement, we enable designers to test how affordable hardware could fit into the assessment of players' states and progress in their particular game using a range of tools.

Lecture Notes in Computer Science, 2015

We report on the results of a study on immersion in an audio-only game with touch-less gesture in... more We report on the results of a study on immersion in an audio-only game with touch-less gesture interaction. A structured design approach to audio feedback that considers the story-context leads to different design approaches: explicit instructions on the one hand and diegetic environmental feedback on the other. Further, we distinguish audio feedback before, during, and after gestures as part of the approach. Two corresponding versions of a gesture-based audio-only story have been implemented and evaluated regarding immersion using a questionnaire study. The findings indicate that replacing explicit audio instructions for hand positions and movements with responsive audio feedback for suggesting interaction methods using environmental story-related audio cues leads to measurably higher story immersion.

Proceedings of the Audio Mostly 2015 on Interaction With Sound - AM '15, 2015

The design of audio feedback for touch-less gesture interaction with audio-only environments requ... more The design of audio feedback for touch-less gesture interaction with audio-only environments requires a structured approach. We present design principles for responsive audio feedback geared towards hand gestures in audio-only games, focusing on diegetic environmental feedback before, during, and after gestures. Illustrations for the principles are drawn from a project investigating the usefulness of different designs for encouraging user participation and maintaining immersion in audio-only games. The findings indicate that replacing explicit audio instructions for hand positions and movements with responsive audio feedback for suggesting interaction methods using environmental story-related audio cues leads to measurably higher immersion. Principles for designing immersive audio feedback responsive to hand gesture interaction in a 3-dimensional space also have implications for virtual reality and the blind community's access to motion-controlled games.