Tiziano Piccardi

I am Tiziano Piccardi, an Assistant Professor in the Computer Science Department at Johns Hopkins University.

My research lies at the intersection of HCI, AI, and Social Computing. I study sociotechnical systems such as social media and Wikipedia, and I design methods to improve them.

Previously, I was a postdoctoral scholar at Stanford University in the HCI group advised by Michael Bernstein. I earned my Ph.D. in Computer Science at EPFL in data science advised by Robert West in the Data Science Lab. During my studies, I spent time at HP Labs (Palo Alto, US) and Xerox Research (Grenoble, France).

Earlier in my career, I co-founded a startup (Widerun), which combined virtual reality with fitness.

Lab

PhD students: Diya SarafDiya Saraf, Ruining HeRuining He

Teaching

JHU

Social Computing (EN.601.796), Fall 2026
Intro to HCI (EN.601.490/690), Spring 2026

EPFL

Applied Data Analysis (CS-401), 2016-2020 (EPFL Teaching Excellence Award)
Business design for IT services (CS-490), 2017-2020
Practice of object-oriented programming (CS-108), 2021

Research - Google Scholar

Publications

  • Evaluating the Quality of LLM Alt-Text for Wikipedia: Insights from Editors, Blind and Low-Vision Users, and Crowdworkers
    Tracy Wei, Tiziano Piccardi, Miriam Redi, Michael Bernstein.
    ASSETS ‘26 Proc. of the International ACM SIGACCESS Conference on Computers and Accessibility

  • Value Misalignment in X’s Feed Algorithm Is a Reflection of Value Tensions in Engagement
    Ziv Epstein, Farnaz Jahanbakhsh, Tiziano Piccardi, Axel Peytavin, Isabel Gallegos, Shardul Sapkota, Dora Zhao, Johan Ugander, Michael S. Bernstein.
    Proceedings of the National Academy of Sciences, 2026
    https://doi.org/10.1073/pnas.2610388123

  • Whose Values? Measuring the (Subjective) Expression of Basic Human Values in Social Media Posts
    Ziv Epstein, Farnaz Jahanbakhsh, Tiziano Piccardi, Isabel Gallegos, Dora Zhao, Johan Ugander, Michael S. Bernstein.
    ICWSM ‘26 Proc. of Conference on Web and Social Media
    https://arxiv.org/abs/2511.08453

  • Reranking Social Media Feeds: A Practical Guide for Field Experiments 🏆
    Tiziano Piccardi, Martin Saveski, Chenyan Jia, Jeffrey Hancock, Jeanne L. Tsai, Michael S. Bernstein.
    ACM Transactions on Social Computing 2026
    https://arxiv.org/abs/2406.19571

  • Value Alignment of Social Media Ranking Algorithms
    Farnaz Jahanbakhsh, Dora Zhao, Tiziano Piccardi, Zachary Robertson, Ziv Epstein, Sanmi Koyejo, Michael S. Bernstein
    CHI ‘26 Proc. of the SIGCHI Conference on Human Factors in Computing Systems
    https://arxiv.org/abs/2509.14434

  • Social Media Feed Elicitation 🏆
    Lindsay Popowski, Xiyuan Wu, Xuyang Zhu, Tiziano Piccardi, Michael S. Bernstein
    CHI ‘26 Proc. of the SIGCHI Conference on Human Factors in Computing Systems https://arxiv.org/abs/2602.18594

  • Reranking partisan animosity in algorithmic social media feeds alters affective polarization
    Tiziano Piccardi, Martin Saveski, Chenyan Jia, Jeffrey Hancock, Jeanne L. Tsai, Michael S. Bernstein.
    Science 2025
    https://www.science.org/doi/10.1126/science.adu5584

  • Alexandria: A Library of Pluralistic Values for Realtime Re-Ranking of Social Media Feeds
    Akaash Kolluri, Renn Su, Farnaz Jahanbakhsh, Dora Zhao, Tiziano Piccardi, Michael S. Bernstein
    ICWSM ‘26 Proc. of Conference on Web and Social Media
    https://arxiv.org/abs/2411.14652

  • Burst: Collaborative Curation in Connected Social Media Communities
    Yutong Zhang, Taeuk Kang, Sydney Yeh, Anavi Baddepudi, Lindsay Popowski, Tiziano Piccardi, Michael S. Bernstein
    CSCW ‘25 Proc. of Conference on Computer-Supported Cooperative Work & Social Computing
    https://arxiv.org/abs/2508.19768

  • Web2Wiki: Characterizing Wikipedia Linking Across the Web
    Veniamin Veselovsky, Tiziano Piccardi, Ashton Anderson, Robert West, Akhil Arora
    ICWSM ‘26 Proc. of Conference on Web and Social Media
    https://arxiv.org/abs/2505.15837

  • Navigating Knowledge: Patterns and Insights from Wikipedia Consumption
    Tiziano Piccardi, Robert West.
    Book chapter - Handbook of Computational Social Science, 2025
    https://arxiv.org/abs/2501.00939

  • In-class Data Analysis Replications: Teaching Students while Testing Science Kristina Gligoric*, Tiziano Piccardi*, Jake Hofman, Robert West. * Equal contribution
    Harvard Data Science Review, 2024
    https://arxiv.org/abs/2308.16491 - Slides

  • AnthroScore: A Computational Linguistic Measure of Anthropomorphism
    Myra Cheng, Kristina Gligoric, Tiziano Piccardi, Dan Jurafsky
    EACL ‘24 Proc. of European Chapter of the Association for Computational Linguistics
    https://arxiv.org/abs/2402.02056

  • Curious Rhythms: Temporal Regularities of Wikipedia Consumption
    Tiziano Piccardi, Martin Gerlach, Robert West.
    ICWSM ‘24 Proc. of Conference on Web and Social Media
    https://arxiv.org/abs/2305.09497 - Poster

  • Embedding Societal Values into Social Media Algorithms
    Michael Bernstein, Angèle Christin, Jeffrey Hancock, Tatsunori Hashimoto, Chenyan Jia, Michelle Lam, Nicole Meister, Nathaniel Persily, Tiziano Piccardi, Martin Saveski, Jeanne Tsai, Johan Ugander, Chunchen Xu.
    Journal of Online Trust and Safety - Vol. 2, No. 1 (2023)
    https://doi.org/10.54501/jots.v2i1.148

More publications…