Ecolor: Synthesis of EInk Microcapsules for Fabricating DIY DisplaysRecent HCI research has explored active materials for programmable displays, yet accessibility remains a key challenge. While some programmable materials, such as thermochromic ink, are widely available, others—like electronic ink (EInk)—remain confined to industrial production. Despite its versatility, EInk is rarely used in HCI due to complex production processes that require expert knowledge in chemistry. We address this limitation by adapting existing microencapsulation techniques from other fields and identifying barriers to broader adoption. We present a simplified, safe, and more accessible method for producing EInk microcapsules. Through a series of analyses, we evaluate the viability of the resulting EInk and we evaluated the process with six participants unfamiliar with EInk fabrication and found it to be accessible and easy to follow. Our work represents a step toward democratizing EInk, bridging the gap between chemical engineering and practical application in HCI, and enabling broader integration of EInk into the design of diverse interactive devices.2025WZWenda Zhao et al.Shape-Changing Interfaces & Soft Robotic MaterialsOn-Skin Display & On-Skin InputShape-Changing Materials & 4D PrintingUIST
Text Entry for XR Trove (TEXT): Collecting and Analyzing Techniques for Text Input in XRText entry for extended reality (XR) is far from perfect, and a variety of text entry techniques (TETs) have been proposed to fit various contexts of use. However, comparing between TETs remains challenging due to the lack of a consolidated collection of techniques, and limited understanding of how interaction attributes of a technique (e.g., presence of visual feedback) impact user performance. To address these gaps, this paper examines the current landscape of XR TETs by creating a database of 176 different techniques. We analyze this database to highlight trends in the design of these techniques, the metrics used to evaluate them, and how various interaction attributes impact these metrics. We discuss implications for future techniques and present TEXT: Text Entry for XR Trove, an interactive online tool to navigate our database.2025ABArpit Bhatia et al.University of Copenhagen, Department of Computer ScienceSocial & Collaborative VRImmersion & Presence ResearchCHI
Rhapso: Automatically Embedding Fiber Materials into 3D Prints for Enhanced InteractivityWe introduce Rhapso, a 3D printing system designed to embed a diverse range of continuous fiber materials within 3D objects during the printing process. This approach enables integrating properties like tensile strength, force storage and transmission, or aesthetic and tactile characteristics, directly into low-cost thermoplastic 3D prints. These functional objects can have intricate actuation, self-assembly, and sensing capabilities with little to no manual intervention. To achieve this, we modify a low-cost Fused Filament Fabrication (FFF) 3D printer, adding a stepper motor-controlled fiber spool mechanism on a gear ring above the print bed. In addition to hardware, we provide parsing software for precise fiber placement, which generates Gcode for printer operation. To illustrate the versatility of our system, we present applications that showcase its extensive design potential. Additionally, we offer comprehensive documentation and open designs, empowering others to replicate our system and explore its possibilities.2024DADaniel Ashbrook et al.3D Modeling & AnimationDesktop 3D Printing & Personal FabricationShape-Changing Materials & 4D PrintingUIST
CRTypist: Simulating Touchscreen Typing Behavior via Computational RationalityTouchscreen typing requires coordinating the fingers and visual attention for button-pressing, proofreading, and error correction. Computational models need to account for the associated fast pace, coordination issues, and closed-loop nature of this control problem, which is further complicated by the immense variety of keyboards and users. The paper introduces CRTypist, which generates human-like typing behavior. Its key feature is a reformulation of the supervisory control problem, with the visual attention and motor system being controlled with reference to a working memory representation tracking the text typed thus far. Movement policy is assumed to asymptotically approach optimal performance in line with cognitive and design-related bounds. This flexible model works directly from pixels, without requiring hand-crafted feature engineering for keyboards. It aligns with human data in terms of movements and performance, covers individual differences, and can generalize to diverse keyboard designs. Though limited to skilled typists, the model generates useful estimates of the typing performance achievable under various conditions.2024DSDanqing Shi et al.Aalto UniversityKnowledge Worker Tools & WorkflowsComputational Methods in HCICHI
AirLogic: Embedding Pneumatic Computation and I/O in 3D Models to Fabricate Electronics-Free Interactive ObjectsResearchers have developed various tools and techniques towards the vision of on-demand fabrication of custom, interactive devices. Recent work has 3D-printed artefacts like speakers, electromagnetic actuators, and hydraulic robots. However, these are non-trivial to instantiate as they require post-fabrication mechanical-- or electronic assembly. We introduce AirLogic: a technique to create electronics-free, interactive objects by embedding pneumatic input, logic processing, and output widgets in 3D-printable models. AirLogic devices can perform basic computation on user inputs and create visible, audible, or haptic feedback; yet they do not require electronic circuits, physical assembly, or resetting between uses. Our library of 13 exemplar widgets can embed \al-style computational capabilities in existing 3D models. We evaluate our widgets' performance---quantifying the loss of airflow (1) in each widget type, (2) based on printing orientation, and (3) from internal object geometry. Finally, we present five applications that illustrate AirLogic's potential.2022VSValkyrie Savage et al.Desktop 3D Printing & Personal FabricationCircuit Making & Hardware PrototypingUIST
Locomotion Vault: the Extra Mile in Analyzing VR Locomotion TechniquesNumerous techniques have been proposed for locomotion in virtual reality (VR). Several taxonomies consider a large number of attributes (e.g., hardware, accessibility) to characterize these techniques. However, finding the appropriate locomotion technique (LT) and identifying gaps for future designs in the high-dimensional space of attributes can be quite challenging. To aid analysis and innovation, we devised Locomotion Vault (https://locomotionvault.github.io/), a database and visualization of over 100 LTs from academia and industry. We propose similarity between LTs as a metric to aid navigation and visualization. We show that similarity based on attribute values correlates with expert similarity assessments (a method that does not scale). Our analysis also highlights an inherent trade-off between simulation sickness and accessibility across LTs. As such, Locomotion Vault shows to be a tool that unifies information on LTs and enables their standardization and large-scale comparison to help understand the space of possibilities in VR locomotion.2021MLMassimiliano Di Luca et al.University of BirminghamImmersion & Presence ResearchCHI
Monotasking or Multitasking: Designing for Crowdworkers' PreferencesCrowdworkers receive no formal training for managing their tasks, time or working environment. To develop tools that support such workers, an understanding of their preferences and the constraints they are under is essential. We asked 317 experienced Amazon Mechanical Turk workers about factors that influence their task and time management. We found that a large number of the crowdworkers score highly on a measure of polychronicity; this means that they prefer to frequently switch tasks and happily accommodate regular work and non-work interruptions. While a preference for polychronicity might equip people well to deal with the structural demands of crowdworking platforms, we also know that multitasking negatively affects workers' productivity. This puts crowdworkers' working preferences into conflict with the desire of requesters to maximize workers' productivity. Combining the findings of prior research with the new knowledge obtained from our participants, we enumerate practical design options that could enable workers, requesters and platform developers to make adjustments that would improve crowdworkers' experiences.2019LLLaura Lascau et al.University College LondonCrowdsourcing Task Design & Quality ControlNotification & Interruption ManagementImpact of Automation on WorkCHI
Why Do You Need This? Selective Disclosure of Data Among Citizen ScientistsRecent scandals involving data from participatory research have contributed to broader public concern about online privacy. Such concerns might make people more reluctant to participate in research that asks them to volunteer personal data, compromising many researchers' data collection. We tested several motivational messages that encouraged participation in a citizen science project. We measured people's willingness to disclose personal information. While participants were less likely to share sensitive data than neutral data, disclosure behaviour was not affected by attitudes to privacy. Importantly, we found that citizen scientists who were exposed to a motivational message that emphasised 'learning' were more likely to share sensitive information than those presented with other types of motivational cues. Our results suggest that priming individuals with motivational messages can increase their willingness to contribute personal data to a project, even if the request pertains to sensitive information.2019ARAnna Rudnicka et al.University College LondonPrivacy by Design & User ControlPrivacy Perception & Decision-MakingCitizen Science & Crowdsourced DataCHI
Repurposing Emoji for Personalised Communication: Why 🍕 means "I love you"The use of emoji in digital communication can convey a wealth of emotions and concepts that otherwise would take many words to express. Emoji have become a popular form of communication, with researchers claiming emoji represent a type of “ubiquitous language” that can span different languages. In this paper however, we explore how emoji are also used in highly personalised and purposefully secretive ways. We show that emoji are repurposed for something other than their “intended” use between close partners, family members and friends. We present the range of reasons why certain emoji get chosen, including the concept of “emoji affordance” and explore why repurposing occurs. Normally used for speed, some emoji are instead used to convey intimate and personal sentiments that, for many reasons, their users cannot express in words. We discuss how this form of repurposing must be considered in tasks such as emoji-based sentiment analysis.2018SWSarah Wiseman et al.Goldsmiths, University of LondonOnline Identity & Self-PresentationCHI
Evaluation beyond Usability: Validating Sustainable HCI ResearchThe evaluation of research artefacts is an important step to validate research contributions. Sub-disciplines of HCI often pursue primary goals other than usability, such as Sustainable HCI (SHCI), HCI for development, or health and wellbeing. For such disciplines, established evaluation methods are not always appropriate or sufficient, and new conventions for identifying, discussing, and justifying suitable evaluation methods need to be established. In this paper, we revisit the purpose and goals of evaluation in HCI and SHCI, and elicit five key elements that can provide guidance to identifying evaluation methods for SHCI research. Our essay is meant as a starting point for discussing current and improving future evaluation practice in SHCI; we also believe it holds value for other subdisciplines in HCI that encounter similar challenges while evaluating their research.2018CRChristian Remy et al.University of ZurichSustainable HCIEcological Design & Green ComputingCHI
HARK No More: On the Preregistration of CHI ExperimentsExperimental preregistration is required for publication in many scientific disciplines and venues. When experimental intentions are preregistered, reviewers and readers can be confident that experimental evidence in support of reported hypotheses is not the result of HARKing, which stands for Hypothesising After the Results are Known. We review the motivation and outcomes of experimental preregistration across a variety of disciplines, as well as previous work commenting on the role of evaluation in HCI research. We then discuss how experimental preregistration could be adapted to the distinctive characteristics of Human-Computer Interaction empirical research, to the betterment of the discipline.2018ACAndy Cockburn et al.University of CanterburyComputational Methods in HCIResearch Ethics & Open ScienceCHI