The Five-volume Set Lncs 12932-12936 Constitutes The Proceedings Of The 18th Ifip Tc 13 International Conference On Human-computer Interaction, Interact 2021, Held In Bari, Italy, In Augustseptember 2021.the Total Of 105 Full Papers Presented Together With 72 Short Papers And 70 Other Papers In These Books Was Carefully Reviewed And Selected From 680 Submissions. The Contributions Are Organized In Topical Sections Named: Part I: Affective Computing; Assistive Technology For Cognition And Neurodevelopment Disorders; Assistive Technology For Mobility And Rehabilitation; Assistive Technology For Visually Impaired; Augmented Reality; Computer Supported Cooperative Work. Part Ii: Covid-19 & Hci; Croudsourcing Methods In Hci; Design For Automotive Interfaces; Design Methods; Designing For Smart Devices & Iot; Designing For The Elderly And Accessibility; Education And Hci; Experiencing Sound And Music Technologies; Explainable Ai.