The four-volume set LNCS 14011, 14012, 14013, and 14014 constitutes the refereed proceedings of the Human Computer Interaction thematic area of the 25th International Conference on Human-Computer Interaction, HCII 2023, which took place in Copenhagen, Denmark, in July 2023. A total of 1578 papers and 396 posters have been accepted for publication in the HCII 2023 proceedings from a total of 7472 submissions. The papers included in the HCI 2023 volume set were organized in topical sections as follows: Part I: Design and evaluation methods, techniques...