Active Edge is a feature of Google Pixel 2 smartphone devices that creates a force-sensitive interaction surface along their sides, allowing users to perform gestures by holding and squeezing their device. Supported by strain gauge elements adhered to the inner sidewalls of the device chassis, these gestures can be more natural and ergonomic than on-screen (touch) counterparts. Developing these interactions is an integration of several components: (1) an insight and understanding of the user experiences that benefit from squeeze gestures; (2) hardware with the sensitivity and reliability to sense a user's squeeze in any operating environment; (3) a gesture design that discriminates intentional squeezes from innocuous handling; and (4) an interaction design to promote a discoverable and satisfying user experience. This paper describes the design and evaluation of Active Edge in these areas as part of the product's development and engineering.

In this paper, we present a recommendation system for the automatic design of magazine covers. Our users are non-designer designers: individuals or small and medium businesses who want to design without hiring a professional designer while still wanting to create aesthetically compelling designs. Because a design should have a purpose, we suggest a number of semantic features to the user, e.g., "clean and clear," "dynamic and active," or "formal," to describe the color mood for the purpose of his/her design. Based on these high level features and a number of low level features, such as the complexity of the visual balance in a photo, our system selects the best photos from the user's album for his/her design. Our system then generates several alternative designs that can be rated by the user. Consequently, our system generates future designs based on the user's style. In this fashion, our system personalizes the designs of a user based on his/her preferences.

Managing large document databases has become an important task. Being able to automatically compare document layouts and classify and search documents with respect to their visual appearance proves to be desirable in many applications. We propose a new algorithm that approximates a metric function between documents based on their visual similarity. The comparison is based only on the visual appearance of the document without taking into consideration its text content. We measure the similarity of single page documents with respect to distance functions between three document components: background, text, and saliency. Each document component is represented as a Gaussian mixture distribution; and distances between the components of different documents are calculated as an approximation of the Hellinger distance between corresponding distributions. Since the Hellinger distance obeys the triangle inequality, it proves to be favorable in the task of nearest neighbor search in a document database. Thus, the computation required to find similar documents in a document database can be significantly reduced.

We present two experiments to evaluate wrist-worn wearable tactile displays (WTDs) that provide easy to perceive alerts for on-the-go users. The first experiment (2304 trials, 12 participants) focuses on the perception sensitivity of tactile patterns and reveals that people discriminate our 24 tactile patterns with up to 99% accuracy after 40 minutes of training. Among the four parameters (intensity, starting point, temporal pattern, and direction) that vary in the 24 patterns, intensity is the most difficult parameter to distinguish and temporal pattern is the easiest. The second experiment (9900 trials, 15 participants) focuses on dual task performance, exploring users' abilities to perceive three incoming alerts from two mobile devices (WTD and mobile phone) with and without visual distraction. The second experiment reveals that, when visually distracted, users' reactions to incoming alerts become slower for the mobile phone but not for the WTD.

The introduction of a new generation of attractive touch screen-based devices raises many basic usability questions whose answers may influence future design and market direction. With a set of current mobile devices, we conducted three experiments focusing on one of the most basic interaction actions on touch screens: the operation of soft buttons. Issues investigated in this set of experiments include: a comparison of soft button and hard button performance; the impact of audio and vibrato-tactile feedback; the impact of different types of touch sensors on use, behavior, and performance; a quantitative comparison of finger and stylus operation; and an assessment of the impact of soft button sizes below the traditional 22 mm recommendation as well as below finger width.

CopyCat is an American Sign Language (ASL) game, which uses gesture recognition technology to help young deaf children practice ASL skills. We describe a brief history of the game, an overview of recent user studies, and the results of recent work on the problem of continuous, user-independent sign language recognition in classroom settings. Our database of signing samples was collected from user studies of deaf children playing aWizard of Oz version of the game at the Atlanta Area School for the Deaf (AASD). Our data set is characterized by disfluencies inherent in continuous signing, varied user characteristics including clothing and skin tones, and illumination changes in the classroom. The dataset consisted of 541 phrase samples and 1,959 individual sign samples of five children signing game phrases from a 22 word vocabulary. Our recognition approach uses color histogram adaptation for robust hand segmentation and tracking. The children wear small colored gloves with wireless accelerometers mounted on the back of their wrists. The hand shape information is combined with accelerometer data and used to train hidden Markov models for recognition. We evaluated our approach by using leave-one-out validation; this technique iterates through each child, training on data from four children and testing on the remaining child's data. We achieved average word accuracies per child ranging from 91.75% to 73.73% for the user-independent models.

We present a design for an interactive American Sign Language game geared for language development for deaf children. In addition to work on game design, we show how Wizard of Oz techniques can be used to facilitate our work on ASL recognition. We report on two Wizard of Oz studies which demonstrate our technique and maximize our iterative design process. We also detail specific implications to the design raised from working with deaf children and possible solutions.