Christoph Riedl

dblp:70/150 · DBLP profile ↗
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14ranked-venue papers
5as first author
5since 2021 · last 2026
0000-0002-3807-6364ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Human-computer interaction and ubiquitous computing · 6 · 2 first-author · 3 since 2021Graphics, computer vision, multimedia, augmented reality and games · 3 · 1 since 2021Artificial intelligence and machine learning · 2 · 1 first-author · 1 since 2021Databases, data management, data science and information retrieval · 2 · 1 first-authorApplied, interdisciplinary, general and emerging computing · 2 · 1 first-author · 1 since 2021Software engineering, systems software and programming languages · 1
YearPublicationVenuePosition
2026 Cognitive Spillover in Human-AI Teams
abstract
AI is not only a neutral tool in team settings; it influence the social and cognitive fabric of collaboration. Across two randomized experiments, we demonstrate that AI exposure produces causal spillover into human–human interaction—affecting shared language, collective attention, shared mental models, and social cohesion. These spillover effects occur robustly across settings, modalities, tasks, and AI qualities, suggesting that mere exposure to AI drives the influence. AI functions as an implicit “social forcefield,” influencing not only how people speak, but also how they think, what they attend to, and how they relate to each other. We argue for shifting the design paradigm from optimizing “AI as a tool” to understanding AI as a socially influential actor whose effects extend beyond the human–AI interface.
Christoph Riedl, Saiph Savage, Josie Zvelebilova
ACM Trans. Comput. Hum. Interact.1
2024 Cooperation in the Gig Economy: Insights from Upwork Freelancers
abstract
Existing literature on online labor markets predominantly focuses on how freelancers individually complete tasks and projects. Our study examines freelancers' willingness to work collaboratively. We report results from a survey of 122 freelancers on a leading online labor market platform (Upwork) that examine freelancers' preferences for collaborative work arrangements, and that explore several antecedents of cooperative behaviors. We then test if actual cooperative behavior matches with freelancers' stated preferences through an incentivized social dilemma experiment. We find that respondents cooperate at a higher rate (85%) than reported in previous comparable studies (between 50-75%). This high rate of cooperation may be explained by an ingroup bias. Using a sequential mediation model, we demonstrate the importance of a sense of shared expectations and accountability for cooperation. We contribute to a better understanding of the potential for collaborative work on online labor market platforms by assessing if and what social factors and collective culture exist among freelancers. We discuss the implications of our results for platform designers by highlighting the importance of platform features that promote shared expectations and improve accountability. Overall, contrary to existing literature and predictions, our results suggest that freelancers in our sample display traits that are more consistent with belonging to a coherent group with a shared collective culture, rather than being anonymous actors in a transaction-based market.
Zachary Fulker, Christoph Riedl
Proc. ACM Hum. Comput. Interact.2
2023 Collective Intelligence in Human-AI Teams: A Bayesian Theory of Mind Approach
abstract
We develop a network of Bayesian agents that collectively model the mental states of teammates from the observed communication. Using a generative computational approach to cognition, we make two contributions. First, we show that our agent could generate interventions that improve the collective intelligence of a human-AI team beyond what humans alone would achieve. Second, we develop a real-time measure of human's theory of mind ability and test theories about human cognition. We use data collected from an online experiment in which 145 individuals in 29 human-only teams of five communicate through a chat-based system to solve a cognitive task. We find that humans (a) struggle to fully integrate information from teammates into their decisions, especially when communication load is high, and (b) have cognitive biases which lead them to underweight certain useful, but ambiguous, information. Our theory of mind ability measure predicts both individual- and team-level performance. Observing teams' first 25% of messages explains about 8% of the variation in final team performance, a 170% improvement compared to the current state of the art.
Samuel Westby, Christoph Riedl
AAAI2
2021 Online Mingling: Supporting Ad Hoc, Private Conversations at Virtual Conferences
abstract
Even though today’s videoconferencing systems are often very useful, these systems do not provide support for one of the most important aspects of in-person meetings: the ad hoc, private conversations that happen before, after, and during the breaks of scheduled events–the proverbial hallway conversations. Here we describe our design of a simple system, called Minglr, which supports this kind of interaction by facilitating the matching of conversational partners. We describe two studies of this system’s use at two virtual conferences with over 450 total participants. Our results provide evidence for the usefulness of this capability, showing that, for example, 81% of people who used the system successfully thought that future virtual conferences should include a tool with similar functionality. We believe that similar functionality is likely to be widely implemented in many videoconferencing systems and to increase the feasibility and desirability of many kinds of remote work and socializing.
Jaeyoon Song 0001, Christoph Riedl, Thomas W. Malone
CHI2
2021 Avoiding the bullies: The resilience of cooperation among unequals
abstract
Can egalitarian norms or conventions survive the presence of dominant individuals who are ensured of victory in conflicts? We investigate the interaction of power asymmetry and partner choice in games of conflict over a contested resource. Previous models of cooperation do not include both power inequality and partner choice. Furthermore, models that do include power inequalities assume a static game where a bully's advantage does not change. They have therefore not attempted to model complex and realistic properties of social interaction. Here, we introduce three models to study the emergence and resilience of cooperation among unequals when interaction is random, when individuals can choose their partners, and where power asymmetries dynamically depend on accumulated payoffs. We find that the ability to avoid bullies with higher competitive ability afforded by partner choice mostly restores cooperative conventions and that the competitive hierarchy never forms. Partner choice counteracts the hyper dominance of bullies who are isolated in the network and eliminates the need for others to coordinate in a coalition. When competitive ability dynamically depends on cumulative payoffs, complex cycles of coupled network-strategy-rank changes emerge. Effective collaborators gain popularity (and thus power), adopt aggressive behavior, get isolated, and ultimately lose power. Neither the network nor behavior converge to a stable equilibrium. Despite the instability of power dynamics, the cooperative convention in the population remains stable overall and long-term inequality is completely eliminated. The interaction between partner choice and dynamic power asymmetry is crucial for these results: without partner choice, bullies cannot be isolated, and without dynamic power asymmetry, bullies do not lose their power even when isolated. We analytically identify a single critical point that marks a phase transition in all three iterations of our models. This critical point is where the first individual breaks from the convention and cycles start to emerge.
Michael Foley, Rory Smead, Patrick Forber, Christoph Riedl
PLoS Comput. Biol.4
2020 Multiparty Visual Co-Occurrences for Estimating Personality Traits in Group Meetings
abstract
Participants’ body language during interactions with others in a group meeting can reveal important information about their individual personalities, as well as their contribution to a team. Here, we focus on the automatic extraction of visual features from each person, including her/his facial activity, body movement, and hand position, and how these features co-occur among team members (e.g., howfre- quently a person moves her/his arms or makes eye contact when she/he is the focus of attention of the group). We correlate these features with user questionnaires to reveal relationships with the "Big Five" personality traits (Openness, Conscientiousness, Extraversion, Agreeableness, Neuroti- cism), as well as with team judgements about the leader and dominant contributor in a conversation. We demonstrate that our algorithms achieve state-of-the-art accuracy with an average of 80% for Big-Five personality trait prediction, potentially enabling integration into automatic group meeting understanding systems.
Lingyu Zhang 0002, Indrani Bhattacharya, Mallory Morgan, Michael Foley, Christoph Riedl, Brooke Foucault Welles, Richard J. Radke
WACV5
2019 Improved Visual Focus of Attention Estimation and Prosodic Features for Analyzing Group Interactions
abstract
Collaborative group tasks require efficient and productive verbal and non-verbal interactions among the participants. Studying such interaction patterns could help groups perform more efficiently, but the detection and measurement of human behavior is challenging since it is inherently multimodal and changes on a millisecond time frame. In this paper, we present a method to study groups performing a collaborative decision-making task using non-verbal behavioral cues. First, we present a novel algorithm to estimate the visual focus of attention (VFOA) of participants using frontal cameras. The algorithm can be used in various group settings, and performs with a state-of-the-art accuracy of 90%. Secondly, we present prosodic features for non-verbal speech analysis. These features are commonly used in speech/music classification tasks, but are rarely used in human group interaction analysis. We validate our algorithms on a multimodal dataset of 14 group meetings with 45 participants, and show that a combination of VFOA-based visual metrics and prosodic-feature-based metrics can predict emergent group leaders with 64% accuracy and dominant contributors with 86% accuracy. We also report our findings on the correlations between the non-verbal behavioral metrics with gender, emotional intelligence, and the Big 5 personality traits.
Lingyu Zhang 0002, Mallory Morgan, Indrani Bhattacharya, Michael Foley, Jonas Braasch, Christoph Riedl, Brooke Foucault Welles, Richard J. Radke
ICMI6
2019 The unobtrusive group interaction (UGI) corpus
abstract
Studying group dynamics requires fine-grained spatial and temporal understanding of human behavior. Social psychologists studying human interaction patterns in face-to-face group meetings often find themselves struggling with huge volumes of data that require many hours of tedious manual coding. There are only a few publicly available multi-modal datasets of face-to-face group meetings that enable the development of automated methods to study verbal and non-verbal human behavior. In this paper, we present a new, publicly available multi-modal dataset for group dynamics study that differs from previous datasets in its use of ceiling-mounted, unobtrusive depth sensors. These can be used for fine-grained analysis of head and body pose and gestures, without any concerns about participants' privacy or inhibited behavior. The dataset is complemented by synchronized and time-stamped meeting transcripts that allow analysis of spoken content. The dataset comprises 22 group meetings in which participants perform a standard collaborative group task designed to measure leadership and productivity. Participants' post-task questionnaires, including demographic information, are also provided as part of the dataset. We show the utility of the dataset in analyzing perceived leadership, contribution, and performance, by presenting results of multi-modal analysis using our sensor-fusion algorithms designed to automatically understand audio-visual interactions.
Indrani Bhattacharya, Michael Foley, Christine Ku, Tongtao Zhang, Cameron Mine, Manling Li, Heng Ji 0001, Christoph Riedl, Brooke Foucault Welles, Richard J. Radke
MMSys9
2018 A Multimodal-Sensor-Enabled Room for Unobtrusive Group Meeting Analysis
abstract
Group meetings can suffer from serious problems that undermine performance, including bias, "groupthink", fear of speaking, and unfocused discussion. To better understand these issues, propose interventions, and thus improve team performance, we need to study human dynamics in group meetings. However, this process currently heavily depends on manual coding and video cameras. Manual coding is tedious, inaccurate, and subjective, while active video cameras can affect the natural behavior of meeting participants. Here, we present a smart meeting room that combines microphones and unobtrusive ceiling-mounted Time-of-Flight (ToF) sensors to understand group dynamics in team meetings. We automatically process the multimodal sensor outputs with signal, image, and natural language processing algorithms to estimate participant head pose, visual focus of attention (VFOA), non-verbal speech patterns, and discussion content. We derive metrics from these automatic estimates and correlate them with user-reported rankings of emergent group leaders and major contributors to produce accurate predictors. We validate our algorithms and report results on a new dataset of lunar survival tasks of 36 individuals across 10 groups collected in the multimodal-sensor-enabled smart room.
Indrani Bhattacharya, Michael Foley, Tongtao Zhang, Christine Ku, Cameron Mine, Heng Ji 0001, Christoph Riedl, Brooke Foucault Welles, Richard J. Radke
ICMI8
2016 Detecting figures and part labels in patents: competition-based development of graphics recognition algorithms
Christoph Riedl, Richard Zanibbi, Marti A. Hearst, Siyu Zhu 0005, Michael Menietti, Jason Crusan, Ivan Metelsky, Karim R. Lakhani
Int. J. Document Anal. Recognit.1
2013 Tweeting to Feel Connected: A Model for Social Connectedness in Online Social Networks
abstract
Social connectedness is an indicator of the extent to which people can realize various network benefits and is therefore a source of social capital. Using the case of Twitter, a theoretical model of social connectedness based on the functional and structural characteristics of people's communication behavior within an online social network is developed and tested. The study investigates how social presence, social awareness, and social connectedness influence each other, and when and for whom the effects of social presence and social awareness are most strongly related to positive outcomes in social connectedness. Specifically, the study looks at the concurrent direct and moderating effect of two structural constructs characterizing people's online social network: network size and frequency of usage. The research model is tested using data (n = 121) collected from two sources: (a) an online survey of Twitter users and (b) their usage data collected directly from Twitter. Results indicate that social awareness, social presence, and usage frequency have a direct effect on social connectedness, whereas network size has a moderating effect. Social presence is found to partially mediate the relationship between social awareness and social connectedness. The findings of the analysis are used to outline design implications for online social networks from a human–computer interaction perspective.
Christoph Riedl, Felix Köbler, Suparna Goswami, Helmut Krcmar
Int. J. Hum. Comput. Interact.1
2010 Conceptualizing a Bottom-Up Approach to Service Bundling
Thomas Kohlborn, Christian Luebeck, Axel Korthaus, Erwin Fielt, Michael Rosemann, Christoph Riedl, Helmut Krcmar
CAiSE6
2009 An Idea Ontology for Innovation Management
abstract
Exchanging and analyzing ideas across different software tools and repositories is needed to implement the concepts of open innovation and holistic innovation management. However, a precise and formal definition for the concept of an idea is hard to obtain. In this paper, the authors introduce an ontology to represent ideas. This ontology provides a common language to foster interoperability between tools and to support the idea life cycle. Through the use of an ontology, additional benefits like semantic reasoning and automatic analysis become available. Our proposed ontology captures both a core idea concept that covers the ‘heart of the idea’ and further concepts to support collaborative idea development, including rating, discussing, tagging, and grouping ideas. This modular approach allows the idea ontology to be complemented by additional concepts like customized evaluation methods. The authors present a case study that demonstrates how the ontology can be used to achieve interoperability between innovation tools and to answer questions relevant for innovation managers that demonstrate the advantages of semantic reasoning.
Christoph Riedl, Norman May, Jan Finzen, Stephan Stathel, Viktor Kaufman, Helmut Krcmar
Int. J. Semantic Web Inf. Syst.1
2008 Quality aspects in service ecosystems: areas for exploitation and exploration
abstract
Service Science, Management, and Engineering (SSME) is a research area with significant relevance to research and practice. Networked systems of web services are a field of service science that enjoys growing interest from researchers. The complex and dynamic environment of these service ecosystems poses new requirements on quality management that are insufficiently addressed by current approaches that focus mainly on the technical aspects of quality. This focus is a severe limitation for the development of service networks because it neglects perceived service quality from the viewpoint of service consumers. In this paper we propose a reference model for quality management in service ecosystems. This reference model is linked in particular to innovation and new service development. Towards the end we propose premises for the implementation and outline a future research agenda.
Christoph Riedl, Tilo Böhmann, Michael Rosemann, Helmut Krcmar
ICEC1