About

S. Shyam Sundar is the Evan Pugh University Professor and James P. Jimirro Professor of Media Effects at the Bellisario College of Communications, Pennsylvania State University. He is the founding director of the Media Effects Research Lab and serves as the Director of the Penn State Center for Socially Responsible Artificial Intelligence. Professor Sundar teaches courses on mass-communication theory, psychology of communication theory, and research methodology. His research focuses on the social and psychological effects of technological elements unique to web-based mass communication. Specifically, his studies investigate how interactivity, navigability, multi-modality, and agency in web interfaces influence online users' thoughts, emotions, and actions.

Research topics

• Computer Science
• Computer Security
• Psychology
• Internet privacy
• World Wide Web
• Social psychology
• Human–computer interaction
• Artificial Intelligence
• Information Retrieval
• Data science
• History
• Business
• Communication
• Applied psychology
• Pedagogy
• Epistemology
• Advertising

Selected publications

• Using LLM for Conversational Assessment of Mental Health: Testing the Role of Message Contingency and User Agency

  2026-04-13

  article
  PublisherDOI

• When AI Disagrees: The Effect of Second Opinion on Patients' Trust in Doctors

  International Journal of Human-Computer Studies · 2026-04-21

  articleSenior author
  PublisherDOI

• Prompt Coaching for Inclusiveness: A Media Literacy Approach to Increase Users’ Awareness of Algorithmic Bias and Prompting Efficacy

  2026-04-13 · 2 citations

  articleOpen accessSenior author

  Large language models often produce biased or stereotypical outputs. One way to reduce this possibility is to be more inclusive in our prompts, but doing so may not come naturally to most users. Therefore, we designed a tool that coaches users to write more inclusive prompts—a strategy that leverages design friction to provide a media literacy intervention. Data from a user study (N=344) show that compared to no coaching, inclusive prompt coaching directly increased users’ awareness of algorithmic bias and their perceived prompting efficacy. It also indirectly enhanced their trust in the system and perceived trust calibration through cognitive elaboration. However, inclusive prompt coaching resulted in a less satisfying user experience. These findings have implications for ethical interventions in prompting for better communicating and combating algorithmic bias. We discuss the benefits and limitations of inclusive prompt coaching, as well as ways to balance usability for long-term adoption of generative AI systems.

  PublisherDOI

• Thriving, Not Just Growing: Structural Sustainability as the Key to Quality in Online Wellness Communities

  2026-04-13 · 1 citations

  articleOpen accessSenior author

  The quality of online wellness communities is difficult to explain using simple growth metrics. However, an empirical understanding of the structural and relational factors that define quality has proven elusive. To fill this gap, we analyzed over 17 million posts from 56 Reddit wellness communities between 2023 and 2024 by applying the sociability-usability framework, measuring user-based factors (e.g., User Retention, Gini Coefficient) and content-based factors (e.g., Interactivity, Quasi-Quality Index), while also examining the impact of identity (Linguistic Distinctiveness and Topic Drift). Our analysis confirmed that quality depends on a stable core user base and meaningful reciprocal exchanges rather than conversation volume. A strong identity creates a trade-off, enhancing internal cohesion while acting as a barrier to new user inflows. Overall, we challenge the conventional ‘growth=success’ paradigm, establishing structural sustainability as the core mechanism for defining quality in online wellness communities and offering a new framework for their design and evaluation.

  PublisherDOI

• How private is private enough? Evaluating facial de-identification across changing social contexts

  Telematics and Informatics · 2025-11-20

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  PublisherDOI

• Financial and regulatory dynamics of food trucks: a biblio-metric synthesis for accounting and economic research

  International Journal of Accounting and Economics Studies · 2025-05-23

  articleOpen access1st authorCorresponding

  This bibliometric review analyzes the scholarly landscape of research on food truck businesses from 2000 to 2025, with a focus on account-‎ing, financial management, and economic regulation. Using a systematic search strategy and bibliometric tools, 243 documents from 185 ‎sources were examined. The analysis identifies growth trends, key contributors, influential publications, and emerging thematic areas within ‎the field. Findings reveal that although research on food trucks has expanded significantly, financial and accounting dimensions remain ‎underexplored compared to themes like food safety and urban governance. Key journals and institutions contributing to the literature were ‎mapped, and patterns of international collaboration were highlighted. Thematic evolution indicates that financial literacy, regulation, and the ‎function of food trucks in urban informal economies are receiving more multidisciplinary attention. This study emphasizes the need for ‎more research to fill in the gaps in food truck entrepreneurs' sustainable business plans, regulatory frameworks, and financial practices. ‎This analysis offers useful insights for scholars, decision-makers, and practitioners working in accounting, economics, and entrepreneurial ‎governance by combining historical patterns and pinpointing areas for future research‎.

  PublisherOA PDFDOI

• Conscious Sedation with Ketamine-Dexmedetomidine Versus Midazolam-Pentazocine in Enhancing Minor Oral Surgery Experience: A Parallel Arm Randomized Clinical Trial

  Journal of Maxillofacial and Oral Surgery · 2025-06-20

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  PublisherDOI

• AI anxiety: Explication and exploration of effect on state anxiety when interacting with AI doctors

  Computers in Human Behavior Artificial Humans · 2025-02-04 · 5 citations

  articleOpen accessSenior author

  People often have anxiety toward artificial intelligence (AI) due to lack of transparency about its operation. This study explicates this anxiety by conceptualizing it as a trait, and examines its effect. It hypothesizes that users with higher AI (trait) anxiety would have higher state anxiety when interacting with an AI doctor, compared to those with lower AI (trait) anxiety, in part because it is a deviation from the status quo of being treated by a human doctor. As a solution, it hypothesizes that an AI doctor's explanations for its diagnosis would relieve patients' state anxiety. Furthermore, based on the status quo bias theory and an adaptation of the theory of interactive media effects (TIME) for the study of human-AI interaction (HAII), this study hypothesizes that the affect heuristic triggered by state anxiety would mediate the causal relationship between the source cue of a doctor and user experience (UX) as well as behavioral intentions. A pre-registered 2 (human vs. AI) x 2 (explainable vs. non-explainable) experiment ( N = 346) was conducted to test the hypotheses. Data revealed that AI (trait) anxiety is significantly associated with state anxiety. Additionally, data showed that an AI doctor's explanations for its diagnosis significantly reduce state anxiety in patients with high AI (trait) anxiety but increase state anxiety in those with low AI (trait) anxiety, but these effects of explanations are not significant among patients who interact with a human doctor. Theoretical and design implications of these findings and limitations of this study are discussed. • AI anxiety: Individual differences in tension, apprehension and worry with arousal due to potential negative impacts of AI. • AI (trait) anxiety is significantly associated with state anxiety. • AI doctor explanations for diagnosis reduce anxiety in high-AI-anxiety patients but increase it in low-AI-anxiety patients.

  PublisherDOI

• Does Transparency Matter When an Ai System Meets Performance Expectations? An Experiment with an Online Dating Site

  SSRN Electronic Journal · 2025-01-01 · 1 citations

  preprintOpen access
  PublisherDOI

• Shorter and Simpler: Customizing Generative AI Responses Can Increase Satisfaction, Credibility, and Fact-Checking Intentions

  2025-04-23 · 1 citations

  articleSenior author
  PublisherDOI

Recent grants

• HCC: Small: Interface Interactivity and User Engagement: A Communications Perspective

  NSF · $446k · 2009–2012

• EAGER: Exploring Heuristics and Designing Interface Cues to Understand Revealing or Withholding of Private Information

  NSF · $278k · 2014–2017

Frequent coauthors

• Ki Joon Kim

  City University of Hong Kong

  24 shared

• Hyang Sook Kim

  23 shared

• Saraswathi Bellur

  22 shared

• Jeeyun Oh

  20 shared

• Haiyan Jia

  Pennsylvania State University

  19 shared

• Mengqi Liao

  Grady Memorial Hospital

  15 shared

• María D. Molina

  Valencia Catholic University Saint Vincent Martyr

  12 shared

• Hyunjin Kang

  Nanyang Technological University

  12 shared

Labs

• Media Effects Research LabPI

  Investigates social and psychological effects of technological elements unique to web-based mass-communication.

Education

• Ph.D., Communication

  University of Illinois at Urbana-Champaign

  1990

• M.A., Communication

  University of Illinois at Urbana-Champaign

  1986

• B.A., Economics

  University of Madras

  1983

Awards & honors

• Penn State Faculty Scholar Medal for outstanding achievement…
• Fellow of the International Communication Association (ICA)
• Frederick Williams Prize awarded by the division for contrib…
• Deutschmann award for research excellence from the Associati…