This two-volume set LNCS 12792 and 12793 constitutes the refereed proceedings of the Third International Conference on Adaptive Instructional Systems, AIS 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 AIS 2021, Part I, are organized in topical sections named: Conceptual Models and Instructional Approaches for AIS; Designing and Developing AIS; Evaluation of AIS; Adaptation Strategies and Methods in AIS. Chapter “Personalized Mastery Learning Ecosystems: Using Bloom’s Four Objects of Change to Drive Learning in Adaptive Instructional Systems” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

This two-volume set LNCS 12792 and 12793 constitutes the refereed proceedings of the Third International Conference on Adaptive Instructional Systems, AIS 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 AIS 2021, Part II, focus on Learner Modelling and State Assessment in AIS.

This book constitutes the refereed proceedings of the 4th International Conference on Adaptive Instructional Systems, AIS 2022, held as part of the 23rd International Conference, HCI International 2022, which was held virtually in June/July 2022. The total of 1271 papers and 275 posters included in the HCII 2022 proceedings was carefully reviewed and selected from 5487 submissions. The AIS 2022 proceedings were organized in the following topical sections: Learner Modeling and State Assessment for Adaptive Instructional Decisions; Adaptation Design to Individual Learners and Teams; Design and Development of Adaptive Instructional Systems; Evaluating the Effectiveness of Adaptive Instructional Systems.

This conference proceeding LNCS 12796 constitutes the thoroughly refereed proceedings of the 2nd International Conference on Design, Operation and Evaluation of Mobile Communications, MOBILE 2021 which was held as part of the 23rd HCI International Conference, HCII 2021 as a virtual event, due to COVID-19, in July 2021. The total of 1276 papers and 241 posters included in the 39 HCII 2021 proceedings volumes were carefully reviewed and selected from 5222 submissions. MOBILE 2021 includes a total of 27 papers; they were organized in topical sections named: Designing, Developing and Evaluating Mobile Interaction Systems and User Experience, Acceptance and Impact of Mobile Communications.

This two-volume set LNCS 12784 and 12785 constitutes the refereed proceedings of the 8th International Conference on Learning and Collaboration Technologies, LCT 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 LCT 2021, Part I, are organized in topical sections named: Designing and Developing Learning Technologies; Learning, Teaching and Collaboration Experiences; On-line vs. in Class Learning in Pandemic Times.

This two-volume set LNCS 12784 and 12785 constitutes the refereed proceedings of the 8th International Conference on Learning and Collaboration Technologies, LCT 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 LCT 2021, Part II, focus on Games and Gamification in Learning; Chatbots in Learning; AR, VR and Robots in Learning.

This book constitutes late breaking papers from the 23rd International Conference on Human-Computer Interaction, HCII 2021, which was held in July 2021. The conference was planned to take place in Washington DC, USA but had to change to a virtual conference mode due to the COVID-19 pandemic. A total of 5222 individuals from academia, research institutes, industry, and governmental agencies from 81 countries submitted contributions, and 1276 papers and 241 posters were included in the volumes of the proceedings that were published before the start of the conference. Additionally, 174 papers and 146 posters are included in the volumes of the proceedings published after the conference, as “Late Breaking Work” (papers and posters). The contributions thoroughly cover the entire field of HCI, addressing major advances in knowledge and effective use of computers in a variety of application areas.

This two-volume set constitutes the refereed proceedings of the 15th International Conference on Universal Access in Human-Computer Interaction, UAHCI 2021, held as part of the 23rd International Conference, HCI International 2021, held as a virtual event, in July 2021. The total of 1276 papers and 241 posters included in the 39 HCII 2021 proceedings volumes was carefully reviewed and selected from 5222 submissions. UAHCI 2021 includes a total of 84 papers; they focus on topics related to universal access methods, techniques and practices, studies on accessibility, design for all, usability, UX and technology acceptance, emotion and behavior recognition for universal access, accessible media, access to learning and education, as well universal access to virtual and intelligent assistive environments.

This book constitutes the refereed proceedings of the Third International Conference on HCI in Mobility, Transport, and Automotive Systems, MobiTAS 2021, held as part of the 23rd International Conference, HCI International 2021, held as a virtual event, in July 2021. The total of 1276 papers and 241 posters included in the 39 HCII 2021 proceedings volumes was carefully reviewed and selected from 5222 submissions. MobiTAS 2021 includes a total of 39 papers which focus on topics related to urban mobility, cooperative and automated mobility, UX in intelligent transportation systems, and mobility for diverse target user groups.

This two-volume set constitutes the refereed proceedings of the 7th International Conference on Human Aspects of IT for the Aged Population, ITAP 2021, held as part of the 23rd International Conference, HCI International 2021, held as a virtual event, in July 2021. The total of 1276 papers and 241 posters included in the 39 HCII 2021 proceedings volumes was carefully reviewed and selected from 5222 submissions. ITAP 2021 includes a total of 67 papers; they focus on topics related to designing for and with older users, technology acceptance and user experience of older users, use of social media and games by the aging population, as well as applications supporting health, wellbeing, communication, social participation and everyday activities.