Users frequently need to enter commands while typing (e.g., for formatting or UI control). These commands usually involve either pointing to GUI controls, which is slow because it requires moving the hand to the mouse, or pressing modifier-based hotkeys, which can be awkward because it requires reaching for the modifier key. Previous research has proposed chording as an alternate mechanism, in which commands are expressed by chording letter keys. Letter chords can be reliably recognized and learned, but previous work does not identify which types of chords are best, and does not assess the performance of letter chords in realistic tasks. We carried out two studies to provide this information: the first measured speed, accuracy, and preference for different types of letter chords; the second evaluates letter-chord performance compared to hotkeys. Our studies identify several features that are important for usable letter chords, and show that in two different tasks, letter chords significantly outperform modifier-based hotkeys by 8-15%.

We 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.

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.

We 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.

Craft and motion are strongly connected, and reflection about this connection enhances our understanding of digital creative experiences. We summarize seven key steps for reflection in craft and create machine-assisted motion-centric tools to support reflection for each key step. These tools reveal different properties of the recorded movement sequence and the relationship between movement and created models. We tested the tools with a sample of novice users who were asked to create a wire-based jewelry model with a set of creation intentions. The resultant qualitative data and visual analysis charts show that introducing the motion information helps the user to meaningfully reflect on their creative experiences and ultimately enhance their decision-making in terms of selecting the models and creating subsequent digital craft-making movements. We therefore hope that our study will stimulate future discussion to bring motion-centric reflection to digital craft processes.

We present IntuModels, a machine-assisted interactive modeling workflow to enable the novice to create 3D models. The workflow uses a phase-driven approach, including idea generation and selection, to stimulate creativity and assist users who are not familiar with generating design ideas and 3D modeling techniques. By transforming parametric models using continual input data controlled by users, IntuModels motivates users to intuitively generate a huge amount of 3D model options with a good diversity. For selecting from the created models, we design a balanced overview showing the models using clustering and staged tools to help the user view and understand the models correctly. We tested IntuModels with a sample of novices who were asked to create a wire-based jewelry model. Presented in thematic networks and quantitative charts, the results showed that the novice considered IntuModels to be intuitive to use and useful for creating models that exceeded their expectations for post-production.

Current wearable AR devices create an isolated experience with a limited field of view, vergence-accommodation conflicts, and difficulty communicating the virtual environment to observers. To address these issues and enable new ways to visualize, manipulate, and share virtual content, we introduce Augmented Augmented Reality (AAR) by combining a wearable AR display with a wearable spatial augmented reality projector. To explore this idea, a system is constructed to combine a head-mounted actuated pico projector with a Hololens AR headset. Projector calibration uses a modified structure from motion pipeline to reconstruct the geometric structure of the pan-tilt actuator axes and offsets. A toolkit encapsulates a set of high-level functionality to manage content placement relative to each augmented display and the physical environment. Demonstrations showcase ways to utilize the projected and head-mounted displays together, such as expanding field of view, distributing content across depth surfaces, and enabling bystander collaboration.

We investigate the performance of one-handed touch input on the side of a mobile phone. A first experiment examines grip change and subjective preference when reaching for side targets using different fingers. Results show all locations can be reached with at least one finger, but the thumb and index are most preferred and require less grip change for positions along the sides. Two following experiments examine taps and flicks using the thumb and index finger in a new two-dimensional input space. A side-touch sensor is simulated with a combination of capacitive sensing and motion tracking to distinguish touches on the lower, middle, or upper edges. When tapping, index and thumb speeds are similar with thumb more accurate and comfortable, and the lower edge is most reliable with the middle edge most comfortable. When flicking with the thumb, the upper edge is fast and rated highly.

MovIPrint is a user-friendly, interactive installation that uses software and a depth-sensing camera to capture human body movement. After inputting digital data such as images or video into the software, MovIPrint offers people innovative and user-friendly ways to explore that data by manipulating it with their body movement. We use media content and/or wireframe design to enable people to then fabricate their own moving images and 3D digital models.

We present TouchSense, which provides additional touchscreen input vocabulary by distinguishing the areas of users' finger pads contacting the touchscreen. It requires minimal touch input area and minimal movement, making it especially ideal for wearable devices such as smart watches and smart glasses. For example, users of a calculator application on a smart watch could tap normally to enter numbers, and tap with the right side of their fingers to enter the operators (e.g. , -, =). Results from two human-factor studies showed that users could tap a touchscreen with five or more distinct areas of their finger pads. Also, they were able to tap with more distinct areas closer to their fingertips. We developed a TouchSense smart watch prototype using inertial measurement sensors, and developed two example applications: a calculator and a text editor. We also collected user feedback via an explorative study.

This paper presents i-m-Cave, a multitouch tabletop system for virtually touring the Mogao Caves. To recreate the experience of such a tour, a field study was conducted, and identified two key design considerations - exploration and restoration. For exploration, an innovative tangible figurine that can perform human-like neck extension/flexion is developed, and users can control the figurine to freely visit every corner of the virtual caves. Furthermore, users can view authorized animations to better understand the story behind important artifacts. With respect to restoration, users can restore digital artifacts and observe the rejuvenation and aging of artifacts with midair hand gestures and mobile devices, as if the users were shuttling back and forth between the present and the past. The i-m-Cave system presents the relationships between presently damaged artifacts and their virtually restored versions, which cannot be experienced in a real tour. Finally, the system was evaluated by interviewing experts. User feedback was positive, indicating the value of the system and its design.