This book constitutes the refereed post-conference proceedings of the Third EAI International Conference on Data and Information in Online Environments, DIONE 2022, held as virtual event, in July 28-29, 2022. Due to COVID-19 pandemic the conference was held virtually. DIONE 2022 aims to bring together academicians and practitioners willing to discuss topics around the intersection of Computer Science, Information Science, and Communication Science. The attractiveness of the scope and topics has brought relevant research results. This proceeding consists of chapters covering deep learning, data management, software design, social networks, natural language processing, and data processing in various contexts like scholarly publishing, health and medicine, higher education, innovation and research, energy and transportation, and organizations. The 18 full papers and 2 short papers were carefully reviewed and selected from 56 submissions. The papers are grouped in thematic sessions as follows: Informational challenges for the study of Science, Technology and Society relationships; and Advances in Artificial Intelligence for data processing and analysis in online social environments.