Writing with AI Lowers Psychological Ownership, but Longer Prompts Can HelpThe feeling of something belonging to someone is called "psychological ownership." A common assumption is that writing with generative AI lowers psychological ownership, but the extent to which this occurs and the role of prompt length are unclear. We report on two experiments to examine the relationship between psychological ownership and prompt length. Participants wrote short stories either completely by themselves or wrote prompts of varying lengths. Results show that when participants wrote longer prompts, they had higher levels of psychological ownership. Their comments suggest they thought more about their prompts, often adding more details about the plot. However, benefits plateaued when prompt length was 75-100% of the target story length. To encourage users to write longer prompts, we propose augmenting the prompt submission button so it must be held down a long time if the prompt is short. Results show that this technique is effective at increasing prompt length.2025NJNikhita Joshi et al.Generative AI (Text, Image, Music, Video)AI-Assisted Creative WritingCUI
Code Shaping: Iterative Code Editing with Free-form AI-Interpreted SketchingWe introduce the concept of code shaping, an interaction paradigm for editing code using free-form sketch annotations directly on top of the code and console output. To evaluate this concept, we conducted a three-stage design study with 18 different programmers to investigate how sketches can communicate intended code edits to an AI model for interpretation and execution. The results show how different sketches are used, the strategies programmers employ during iterative interactions with AI interpretations, and interaction design principles that support the reconciliation between the code editor and sketches. Finally, we demonstrate the practical application of the code shaping concept with two use case scenarios, illustrating design implications from the study.2025RYRyan Yen et al.University of Waterloo, School of Computer Science; MIT, CSAILGenerative AI (Text, Image, Music, Video)Human-LLM CollaborationAI-Assisted Creative WritingCHI
Intermittent Interaction in Digital Fabrication: User Perception of Periodic Intervention in Semi-Automated Creation TasksIntermittent Interaction is a turn-taking approach used to interact with fabrication devices to do something that otherwise would be impractical or impossible for the machine. We investigate how people perceive intermittent interactions in a controlled study. A LEGO assembly task with timed lock boxes simulates human involvement with a semi-automated machine process, similar to a 3D printer. This is used in an in situ study with 12 participants over 4-hour sessions with experimental controls for number of interactions and step complexity. Results suggest complex interactions during assembly can amplify the perceived value of the assembled object and increase enjoyment. Participants used either a clustered or evenly distributed strategy to schedule interactions, which can be modelled with simple heuristics. We contribute evidence that intermittent interaction is generally acceptable for creation tasks and practical guidelines for integrating intermittent interactions into semi-automated fabrication systems.2025LWLudwig Wilhelm Wall et al.University of Waterloo, Cheriton School of Computer ScienceDesktop 3D Printing & Personal FabricationCustomizable & Personalized ObjectsCHI
Understanding Marine Scientist Software Tool UseMarine science researchers are heavy users of software tools and systems such as statistics packages, visualization tools, and online data catalogues. Following a constructivist grounded theory approach, we conduct a semi-structured interview study of 23 marine science researchers and research supports within a North American university, to understand their perceptions of and approaches towards using both graphical and code-based software tools and systems. We propose the concept of fragmentation to represent how various factors lead to isolated pockets of views and practices concerning software tool use during the research process. These factors include informal learning of tools, preferences towards doing things from scratch, and a push towards more code-based tools. Based on our findings, we suggest design priorities for user interfaces that could more effectively help support marine scientists make and use software tools and systems.2025MLMatthew Lakier et al.University of Waterloo, Cheriton School of Computer ScienceVisualization Perception & CognitionMedical & Scientific Data VisualizationCHI
MotionBlocks: Modular Geometric Motion Remapping for More Accessible Upper Body Movement in Virtual RealityMovement-based spatial interaction in VR can present significant challenges for people with limited mobility, particularly due to the mismatch between the upper body motion a VR app requires and the user's capabilities. We describe MotionBlocks, an approach which enables 3D spatial input with smaller motions or simpler input devices using modular geometric motion remapping. A formative study identifies common accessibility issues within VR motion design, and informs a design language of VR motions that fall within simple geometric primitives. These 3D primitives enable collapsing spatial or non-spatial input into a normalized input vector, which is then expanded into a second 3D primitive representing larger, more complex 3D motions. An evaluation with people with mobility limitations found that using geometric primitives for highly customized upper body input remapping reduced physical workload, temporal workload, and perceived effort.2025JWJohann Wentzel et al.University of Waterloo, School of Computer ScienceFull-Body Interaction & Embodied InputMotor Impairment Assistive Input TechnologiesSpecial Education TechnologyCHI
Gait Gestures: Examining Stride and Foot Strike Variation as an Input Method While WalkingWalking is a cyclic pattern of alternating footstep strikes, with each pair of steps forming a stride, and a series of strides forming a gait. We conduct a systematic examination of different kinds of intentional variations from a normal gait that could be used as input actions without interrupting overall walking progress. A design space of 22 candidate Gait Gestures is generated by adapting previous standing foot input actions and identifying new actions possible in a walking context. A formative study (n=25) examines movement easiness, social acceptability, and walking compatibility with foot movement logging to calculate temporal and spatial characteristics. Using a categorization of these results, 7 gestures are selected for a wizard-of-oz prototype demonstrating an AR interface controlled by Gait Gestures for ordering food and audio playback while walking. As a technical proof-of-concept, a gait gesture recognizer is developed and tested using the formative study data.2024CTChing-Yi Tsai et al.Foot & Wrist InteractionAR Navigation & Context AwarenessPrototyping & User TestingUIST
The Effects of Update Interval and Reveal Method on Writer Comfort in Synchronized Shared-EditorsSynchronized shared-editors like Google Docs allow people to write together, but there is no “privacy of writing” which can make writers feel uncomfortable. We propose methods to give writers more control over when and how their edits are shown to collaborators to increase comfort. These are in the form of different update strategies composed of an update interval and a reveal method. Results from an experiment with simulated observers show that alternative update strategies can be beneficial, each having their own pros and cons. A follow-up experiment with writer and observer pairs validates these findings and shows that observers are amenable to experiencing short delays caused by alternative update strategies. Our work shows that synchronous writing tools should support alternative update strategies that preserve both collaborator awareness and writer comfort.2024YYYen-Ting Yeh et al.University of WaterlooCreative Collaboration & Feedback SystemsDistributed Team CollaborationPrototyping & User TestingCHI
Constrained Highlighting in a Document Reader can Improve Reading ComprehensionHighlighting text in a document is a common active reading strategy to remember information from documents. Learning theory suggests that for highlights to be effective, readers must be selective with what they choose to highlight. We investigate if an imposed user interface constraint limiting the number of highlighted words in a document reader can improve reading comprehension. A large-scale between-subjects experiment shows that constraining the number of words that can be highlighted leads to higher reading comprehension scores than highlighting nothing or highlighting an unlimited number of words. Our work empirically validates theories in psychology, which in turn enables several new research directions within HCI.2024NJNikhita Joshi et al.University of WaterlooVisualization Perception & CognitionCHI
Mindful Scroll: An Infinite Scroll Abstract Colouring App for MindfulnessWe design and evaluate Mindful Scroll, a mobile application for mindfulness that encourages a slow and deliberate approach to colouring. The app renders an infinite scroll of generated geometric tilings that reveal pseudo-random colour palettes and fill effects when coloured using a finger or pen. A five-day study (N=28) evaluated the efficacy of the app in reducing anxiety and enhancing mindfulness. The results indicate that the app is capable of promoting a greater sense of mindfulness over time and produced similar results across several measures compared to traditional structured colouring and existing mindfulness-based mobile applications. All participants expressed a desire to use the app again, with a majority stating they felt more mindful after the study.2024SZSaralin Zassman et al.University of WaterlooMental Health Apps & Online Support CommunitiesInclusive DesignCHI
SwitchSpace: Understanding Context-Aware Peeking Between VR and Desktop InterfacesCross-reality tasks, like creating or consuming virtual reality (VR) content, often involve inconvenient or distracting switches between desktop and VR. An initial formative study explores cross-reality switching habits, finding most switches are momentary "peeks" between interfaces, with specific habits determined by current context. The results inform a design space for context-aware "peeking" techniques that allow users to view or interact with desktop from VR, and vice versa, without fully switching. We implemented a set of peeking techniques and evaluated them in two levels of a cross-reality task: one requiring only viewing, and another requiring input and viewing. Peeking techniques made task completion faster, with increased input accuracy and reduced perceived workload.2024JWJohann Wentzel et al.University of WaterlooMixed Reality WorkspacesContext-Aware ComputingCHI
Single-handed Folding Interactions with a Modified Clamshell Flip PhoneWe explore and evaluate single-handed folding interactions suitable for “modified clamshell flip phones” with a full screen touch display that folds in half along the short dimension. Three categories of interactions are identified: only-fold, touch-enhanced fold, and fold-enhanced touch; in which gestures are created using fold direction, fold magnitude, and touch position. A prototype evaluation device is built to resemble clamshell flip phones, but with a modified hinge and spring system to enable folding in both directions. A study investigates performance and preference for 30 fold gestures to discover which are most promising. To demonstrate how folding interactions could be incorporated into flip phone interfaces, applications such as map browsing, text editing, and menu shortcuts are described.2024YYYen-Ting Yeh et al.University of WaterlooShape-Changing Interfaces & Soft Robotic Materials360° Video & Panoramic ContentCHI
Digital Knick-Knacks: Standalone Audiovisual Digital Possessions or Embellishments in Digital EnvironmentsInspired by physical possessions displayed in the home, we define "digital knick-knacks" as standalone audiovisual digital possessions or embellishments contained within non-game digital environments. "Neko", a cat that chases the cursor, is a historical example. We propose a taxonomy to define and generate digital knick-knacks based on key publications on consumer behaviour and personal possessions, augmented by results of a brainstorming session with 9 HCI researchers. Using the taxonomy, we prototype three classes of digital knick-knack exemplars: an ambient noise machine, a virtual pet, and a virtual picture frame. In a 10-day diary study, 10 participants design their own variants of the prototypes, and report on their experience using them on a personal device. Our analysis shows how digital knick-knacks can bring value to users, and we suggest implications for designing playful digital embellishments.2024MLMatthew Lakier et al.University of WaterlooDigital Art Installations & Interactive PerformanceInteractive Narrative & Immersive StorytellingCHI
DirectGPT: A Direct Manipulation Interface to Interact with Large Language ModelsWe characterize and demonstrate how the principles of direct manipulation can improve interaction with large language models. This includes: continuous representation of generated objects of interest; reuse of prompt syntax in a toolbar of commands; manipulable outputs to compose or control the effect of prompts; and undo mechanisms. This idea is exemplified in DirectGPT, a user interface layer on top of ChatGPT that works by transforming direct manipulation actions to engineered prompts. A study shows participants were 50% faster and relied on 50% fewer and 72% shorter prompts to edit text, code, and vector images compared to baseline ChatGPT. Our work contributes a validated approach to integrate LLMs into traditional software using direct manipulation. Data, code, and demo available at https://osf.io/3wt6s.2024DMDamien Masson et al.University of WaterlooHuman-LLM CollaborationExplainable AI (XAI)AI-Assisted Decision-Making & AutomationCHI
Transferable Microgestures Across Hand Posture and Location Constraints: Leveraging the Middle, Ring, and Pinky FingersMicrogestures can enable auxiliary input when the hands are occupied. Although prior work has evaluated the comfort of microgestures performed by the index finger and thumb, these gestures cannot be performed while the fingers are constrained by specific hand locations or postures. As the hand can be freely positioned with no primary posture, partially constrained while forming a pose, or highly constrained while grasping an object at a specific location, we leverage the middle, ring, and pinky fingers to provide additional opportunities for auxiliary input across varying levels of hand constraints. A design space and applications demonstrate how such microgestures can transfer across hand location and posture constraints. An online study evaluated their comfort and effort and a lab study evaluated their use for task-specific microinteractions. The results revealed that many middle finger microgestures were comfortable, and microgestures performed while forming a pose were preferred over baseline techniques.2023NJNikhita Joshi et al.Full-Body Interaction & Embodied InputFoot & Wrist InteractionUIST
Statslator: Interactive Translation of NHST and Estimation Statistics Reporting Styles in Scientific DocumentsInferential statistics are typically reported using p-values (NHST) or confidence intervals on effect sizes (estimation). This is done using a range of styles, but some readers have preferences about how statistics should be presented and others have limited familiarity with alternatives. We propose a system to interactively translate statistical reporting styles in existing documents, allowing readers to switch between interval estimates, p-values, and standardized effect sizes, all using textual and graphical reports that are dynamic and user customizable. Forty years of CHI papers are examined. Using only the information reported in scientific documents, equations are derived and validated on simulated datasets to show that conversions between p-values and confidence intervals are accurate. The system helps readers interpret statistics in a familiar style, compare reports that use different styles, and even validate the correctness of reports. Code and data: https://osf.io/x4ue72023DMDamien Masson et al.Interactive Data VisualizationTime-Series & Network Graph VisualizationUIST
Substiports: User-Inserted Ad Hoc Objects as Reusable Structural Support Replacements for Unmodified FDM 3D PrintersWe contribute a technical solution to reduce print time and material with unmodified fused deposition modelling printers. The approach uses ad hoc objects inserted by a user during printing as a replacement for printed support of overhanging structures. Examples of objects include household items like books, toy bricks, and custom mechanisms like a screw jack. A software-only system is integrated into existing slicing software to analyze generated support print paths, search a library of objects to find suitable replacements, optimize combinations of replacement objects, and make necessary adjustments to impacted printing layers and paths. During printing, the user is prompted to insert objects with the help of lightweight printed holders to guide placement and prevent movement. Instructions printed on the build-plate help identify and position objects. A technical evaluation measures performance and benefits with different sets of ad hoc objects and different levels of user involvement.2023LWLudwig Wilhelm Wall et al.Desktop 3D Printing & Personal FabricationUIST
ChartDetective: Easy and Accurate Interactive Data Extraction from Complex Vector ChartsExtracting underlying data from rasterized charts is tedious and inaccurate; values might be partially occluded or hard to distinguish, and the quality of the image limits the precision of the data being recovered. To address these issues, we introduce a semi-automatic system leveraging vector charts to extract the underlying data easily and accurately. The system is designed to make the most of vector information by relying on a drag-and-drop interface combined with selection, filtering, and previsualization features. A user study showed that participants spent less than 4 minutes to accurately recover data from charts published at CHI with diverse styles, thousands of data points, a combination of different encodings, and elements partially or completely occluded. Compared to other approaches relying on raster images, our tool successfully recovered all data, even when hidden, with a 78% lower relative error.2023DMDamien Masson et al.University of WaterlooInteractive Data VisualizationData StorytellingVisualization Perception & CognitionCHI
Charagraph: Interactive Generation of Charts for Realtime Annotation of Data-Rich ParagraphsDocuments often have paragraphs packed with numbers that are difficult to extract, compare, and interpret. To help readers make sense of data in text, we introduce the concept of Charagraphs: dynamically generated interactive charts and annotations for in-situ visualization, comparison, and manipulation of numeric data included within text. Three Charagraph characteristics are defined: leveraging related textual information about data; integrating textual and graphical representations; and interacting at different contexts. We contribute a document viewer to select in-text data; generate and customize Charagraphs; merge and refine a Charagraph using other in-text data; and identify, filter, compare, and sort data synchronized between text and visualization. Results of a study show participants can easily create Charagraphs for diverse examples of data-rich text, and when answering questions about data in text, participants were more correct compared to only reading text.2023DMDamien Masson et al.University of WaterlooInteractive Data VisualizationData StorytellingCHI
Phone Sleight of Hand: Finger-Based Dexterous Gestures for Physical Interaction with Mobile PhonesWe identify and evaluate single-handed “dexterous gestures” to physically manipulate a phone using the fine motor skills of fingers. Four manipulations are defined: shift, spin (yaw axis), rotate (roll axis) and flip (pitch axis), with a formative survey showing all except flip have been performed for various reasons. A controlled experiment examines the speed, behaviour, and preference of manipulations in the form of dexterous gestures, by considering two directions and two movement magnitudes. Results show rotate is rated as easiest and most comfortable, while flip is rated lowest. Using a heuristic recognizer for spin, rotate, and flip, a one-week usability experiment finds increased practice and familiarity improve the speed and comfort of dexterous gestures. Design guidelines are developed to consider comfort, ability, and confidence when mapping dexterous gestures to interactions, and demonstrations show how such gestures can be used in smartphone applications.2023YYYen-Ting Yeh et al.University of WaterlooHand Gesture RecognitionFoot & Wrist InteractionCHI
Evaluating Across-Hinge Dragging with Pen and Touch on Curved and Foldable DisplaysFoldable touch screens are increasingly popular, but little research has explored how the hinge impacts usability and performance. We evaluate across- and along-hinge drag gestures on a series of prototypes emulating foldable all-screen laptops with a curved hinge radius ranging from 1mm to 24mm. Results show that using a large 24mm hinge radius instead of a small 1mm hinge radius can decrease drag time by 13% and movement variability by 7% for touch input. However, hinge radius had no effect on performance for pen input. Further, we found that dragging along the hinge was up to 30% faster than dragging across the hinge, especially when dragging across at an acute angle to the hinge. Using these results, we demonstrate use cases for across- and along-hinge gestures. Our findings provide guidance for hardware and interaction designers seeking to create foldable touchscreen devices and their accompanying software.2023GZGraeme Zinck et al.University of WaterlooShape-Changing Interfaces & Soft Robotic MaterialsPrototyping & User TestingCHI