AI capabilities for document reader software are usually presented in separate chat interfaces. We explore integrating AI into document comments, a concept we formalize as AI margin notes. Three design parameters characterize this approach: margin notes are integrated with the text while chat interfaces are not; selecting text for a margin note can be automated through AI or manual; and the generation of a margin note can involve AI to various degrees. Two experiments investigate integration and selection automation, with results showing participants prefer integrated AI margin notes and manual selection. A third experiment explores human and AI involvement through six alternative techniques. Techniques with less AI involvement resulted in more psychological ownership, but faster and less effortful designs were generally preferred. Surprisingly, the degree of AI involvement had no measurable effect on reading comprehension. Our work shows that AI margin notes are desirable and contributes implications for their design.

Highlighting 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.

Synchronized 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.

Spatial augmented reality (SAR) can extend desktop computing out of the monitor and into our surroundings, but extending the standard style of mouse input is challenging due to real-world geometry irregularity, gaps, and occlusion. We identify two general approaches for controlling a mouse cursor in SAR: perspective-based approaches based on raycasting, such as Nacenta et. al’s Perspective Cursor, and geometry-based approaches that closely associate cursor movement with surface topology. For the latter, we introduce Everywhere Cursor, a geometry-based approach for indirect mouse cursor control for complex 3D surface geometry in SAR. A controlled experiment compares approaches. Results show the geometry-based Everywhere Cursor improves accuracy and precision by 29% to 60% on average in a tracing task, but when traversing long distances, the perspective-based Perspective Cursor and Raycasting techniques are 22% to 49% faster, albeit with 4% to 10% higher error rates.

Microgestures 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.

People often have to remove their phone from an inaccessible location like a pocket to view things like notifications and directions. We explore the idea of viewing such information through the fabric of a pocket using low resolution bright LED matrix displays. A survey confirms viewing information on inaccessible phones is desirable, and establishes types of pockets in garments worn by respondents and what objects are typically put in pockets. A technical evaluation validates that LED light can shine through many common garment fabrics. Based on these results, functional hardware prototypes are constructed to demonstrate different form factors of through-fabric display devices, such as a phone, wallet, a key fob, a pen, and earbud headphone case. A simple interaction vocabulary for viewing key information on these devices is described, and the social and technical aspects of the approach are discussed.

While synchronous one-on-one help for software learning is rich and valuable, it can be difficult to find and connect with someone who can provide assistance. Through a formative user study, we explore the idea of fixed-duration, one-on-one help sessions and find that 3 minutes is often enough time for novice users to explain their problem and receive meaningful help from an expert. To facilitate this type of interaction, we developed MicroMentor, an on-demand help system that connects users via video chat for 3-minute help sessions. MicroMentor automatically attaches relevant supplementary materials and uses contextual information, such as command history and expertise, to encourage the most qualified users to accept incoming requests. These help sessions are recorded and archived, building a bank of knowledge that can further help a broader audience. Through a user study, we find MicroMentor to be useful and successful in connecting users for short teaching moments.

Tables, desks, and counters are often nearby, motivating their use as interactive surfaces. However, they are typically cluttered. As an alternative, we explore touch input along the 'edge' of table-like surfaces. The performance of tapping, crossing, and dragging is tested along the two ridges and front face of a table edge. Results show top ridge movement time is comparable to the top face when tapping or dragging. When crossing, both ridges are at least 11% faster than the top face. Effective width analysis is used to model performance and provide recommended target sizes. Based on observed user behaviour, variations of top and bottom ridge crossing are explored in a second study, and design recommendations with example applications are provided.