Quantifying Polarization on Twitter: the Kavanaugh Nomination -- Understanding Gray Networks Using Social Media Trace Data -- Predicting Audience Engagement Across Social Media Platforms in the News Domain -- Stylistic Features Usage: Similarities and Di↵erences Using Multiple Social Networks -- Do Events change Opinions on Social media? Studying the 2016 US Presidential Debates -- "Hashjacking" the Debate: Polarisation Strategies of Germany's political far-right on Twitter -- Airbnb's reputation system and gender differences among guests: Evidence from large-scale data analysis and a controlled experiment -- Deep Dive into Anonymity: Large Scale Analysis of Quora Questions -- GenderandRacialDiversityinCommercialBrands' AdvertisingImagesonSocialMedia -- Measuring Personal Values in Cross-Cultural User-Generated Content -- Arabic Offensive Language Classification on Twitter -- Into the Dark: A Case Study of Banned Darknet Drug Forums -- Arabs and Atheism: Religious Discussions in the Arab Twittersphere -- A VOICE FOR EDUCATION: A DIGITAL ANALYSIS OF SHEIKHA MOZA'S PUBLIC STATEMENTS, 2009-2018 -- Did the Black Panther movie make Blacks blacker? Examining black racial identity on Twitter before and after the Black Panther movie release -- Assessing Sentiment of the Expressed Stance on Social Media -- You can't see what you can't see: Experimental evidence for how much relevant information may be missed due to Google's Web search personalization -- A Longitudinal Study on Twitter-Based Forecasting of Five Dutch National Elections -- Housing in Affluent vs. Deprived Areas: An Analysis of Online Housing Advertisements in Dublin -- Perceptions of Social Roles Across Cultures -- The demography of the peripatetic researcher: Evidence on highly mobile scholars from the Web of Science -- Using Simulated Reproductive History Data to Re-think the Relationship Between Education and Fertility.

This volume constitutes the proceedings of the 11th International Conference on Social Informatics, SocInfo 2019, held in Doha, Qatar, in November 2019. The 17 full and 5 short papers presented in these proceedings were carefully reviewed and selected from 86 submissions. The papers presented in this volume cover a broad range of topics, ranging from the study of socio-technical systems, to computer science methods to analyze complex social processes, as well as social concepts in the design of information systems.