I am a PhD candidate in Sociology at the University of Mannheim where I research the quality of new data sources and methods for the social sciences. I am excited about innovative data and methods to approach social science questions from a new perspective. At the same time, I take a critical look at the limitations and challenges for data quality that come with these data sources and methods, including social media data, API-based data, web tracking data, and LLMs.

I joined the Chair of Social Data Science and Methodology at the University of Mannheim in August 2021 as a PhD candidate supervised by Florian Keusch. Besides my research, I teach quantitative methods courses in the Sociology Bachelor’s program.

I hold a Bachelor’s and Master’s degree in Sociology from the Otto-Friedrich-Universität Bamberg, Germany, and a Master’s degree in Sociology and Social Research from the University of Trento, Italy. Before my PhD, I worked as a research assistant in the project Refugees in the German Educational System at the LIfBi where I primarily worked on data validation.

Current Projects

• “My (22m) Girlfriend (23f) Comes Home and Does Nothing” — Gendered Perceptions of Paid and Unpaid Work in Reddit Relationship Discussions over Time: Together with Birgit Zeyer Gliozzo, Gundula Zoch, and Philipp Doebler, we examine how well LLMs can annotate manifest and latent constructs in Reddit posts. Building on these annotations, we study how male and female Redditors discuss relationship conflicts around paid and household labor over time.
• Gendered Communication in German Political Interview Podcasts Through Multimodal Data: I investigate whether interviewers treat men and women differently in political interviews, drawing on multimodal data from podcast episodes.

Publications

Johanna Hölzl, Florian Keusch, John Collins (2026). ‘Where You Are Is What You Get! Inconsistencies of Digital Trace Data Across Download Locations’. Social Science Computer Review 0(0). DOI: 10.1177/08944393261469494.

Johanna Hölzl, Florian Keusch, Christoph Sajons (2025). ‘The (mis)use of Google Trends data in the social sciences — A systematic review, critique, and recommendations’. Social Science Research 126(103099). DOI: 10.1016/j.ssresearch.2024.103099

Johanna Hölzl, Daria Szafran, Florian Keusch (2025). ‘Digitale Ungleichheiten in Deutschland’. GESIS Data Archive. DOI: 10.7802/2915

Johanna Hölzl, Marie-Lou Sohnius (2023). ‘Spotify API’. In APIs for social scientists: A collaborative review, edited by P. C. Bauer, C. Landesvatter, and L. Behrens.