This two-volume set LNCS 12194 and 12195 constitutes the refereed proceedings of the 12th International Conference on Social Computing and Social Media, SCSM 2020, held as part of the 22nd International Conference, HCI International 2020, which was planned to be held in Copenhagen, Denmark, in July 2020. The conference was held virtually due to the COVID-19 pandemic. The total of 1439 papers and 238 posters have been accepted for publication in the HCII 2020 proceedings from a total of 6326 submissions. SCSM 2020 includes a total of 93 papers which are organized in topical sections named: Design Issues in Social Computing, Ethics and Misinformation in Social Media, User Behavior and Social Network Analysis, Participation and Collaboration in Online Communities, Social Computing and User Experience, Social Media Marketing and Consumer Experience, Social Computing for Well-Being, Learning, and Entertainment.

Uncovers the growing and expanding phenomenon of human behavior, social constructs, and communication in online environments.

This two-volume set LNCS 12194 and 12195 constitutes the refereed proceedings of the 12th International Conference on Social Computing and Social Media, SCSM 2020, held as part of the 22nd International Conference, HCI International 2020, which was planned to be held in Copenhagen, Denmark, in July 2020. The conference was held virtually due to the COVID-19 pandemic. The total of 1439 papers and 238 posters have been accepted for publication in the HCII 2020 proceedings from a total of 6326 submissions. SCSM 2020 includes a total of 93 papers which are organized in topical sections named: Design Issues in Social Computing, Ethics and Misinformation in Social Media, User Behavior and Social Network Analysis, Participation and Collaboration in Online Communities, Social Computing and User Experience, Social Media Marketing and Consumer Experience, Social Computing for Well-Being, Learning, and Entertainment.

This two-volume set LNCS 12774 and 12775 constitutes the refereed proceedings of the 13th International Conference on Social Computing and Social Media, SCSM 2021, held as part of the 23rd International Conference, HCI International 2021, which took place in July 2021. Due to COVID-19 pandemic the conference was held virtually. The total of 1276 papers and 241 posters included in the 39 HCII 2021 proceedings volumes was carefully reviewed and selected from 5222 submissions. The papers of SCSM 2021, Part I, are organized in topical sections named: Computer Mediated Communication; Social Network Analysis; Experience Design in Social Computing.

This two-volume set LNCS 11578 and 11579 constitutes the refereed proceedings of the 11th International Conference on Social Computing and Social Media, SCSM 2019, held in July 2019 as part of HCI International 2019 in Orlando, FL, USA. HCII 2019 received a total of 5029 submissions, of which 1275 papers and 209 posters were accepted for publication after a careful reviewing process. The 81 papers presented in these two volumes are organized in topical sections named: Social Media Design and Development, Human Behaviour in Social Media, Social Network Analysis, Community Engagement and Social Participation, Computer Mediated Communication, Healthcare Communities, Social Media in Education, Digital Marketing and Consumer Experience.

This two-volume set LNCS 12774 and 12775 constitutes the refereed proceedings of the 13th International Conference on Social Computing and Social Media, SCSM 2021, held as part of the 23rd International Conference, HCI International 2021, which took place in July 2021. Due to COVID-19 pandemic the conference was held virtually. The total of 1276 papers and 241 posters included in the 39 HCII 2021 proceedings volumes was carefully reviewed and selected from 5222 submissions. The papers of SCSM 2021, Part I, are organized in topical sections named: Computer Mediated Communication; Social Network Analysis; Experience Design in Social Computing.

The three-volume set LNCS 12181, 12182, and 12183 constitutes the refereed proceedings of the Human Computer Interaction thematic area of the 22nd International Conference on Human-Computer Interaction, HCII 2020, which took place in Copenhagen, Denmark, in July 2020.* A total of 1439 papers and 238 posters have been accepted for publication in the HCII 2020 proceedings from a total of 6326 submissions. The 145 papers included in this HCI 2020 proceedings were organized in topical sections as follows: Part I: design theory, methods and practice in HCI; understanding users; usability, user experience and quality; and images, visualization and aesthetics in HCI. Part II: gesture-based interaction; speech, voice, conversation and emotions; multimodal interaction; and human robot interaction. Part III: HCI for well-being and Eudaimonia; learning, culture and creativity; human values, ethics, transparency and trust; and HCI in complex environments. *The conference was held virtually due to the COVID-19 pandemic.