This post-conference book constitutes selected papers of the Fifth International Conference on Computer-Human Interaction Research and Applications, CHIRA 2021, held virtually due to COVID 19, and Sixth International Conference on Computer-Human Interaction Research and Applications, CHIRA 2022, held in Valletta, Malta, in October 2022. The 8 full papers presented in this book were carefully reviewed and selected from 48 submissions for CHIRA 2021 and 37 submissions for CHIRA 2022. The papers selected to be included in this book contribute to the understanding of relevant trends of current research on computer-human interaction, including user-centered interaction design patterns, user experience design, multimedia and multimodal Interaction, interaction design modelling, haptic and tangible devices, accessible and adaptive interaction, user behaviour analysis, user experience evaluation, modelling human factors, mobile computer-human interaction, machine learning, information retrieval, human-centered AI and design and evaluation.