This paper presents a renewed overview of photosensor oculography (PSOG), an eye-tracking technique based on the use of simple photosensors (usually infrared) to measure the overall amount of reflected light while the eye rotates. PSOG can provide high spatial and temporal resolution, low tracking latency, and reduced power consumption. The deeper examination of this technique is particularly important, given the current needs for efficient eye-tracking mechanisms by the emerging interaction devices, e.g., augmented and virtual reality headsets. In our investigation, we employ an adjustable simulation framework to examine the eye-tracking performance when changing the parameters of different PSOG designs. We focus our examination on eye-tracking accuracy and crosstalk, two crucial characteristics for the seamless interaction via eye-tracking. Our experiments demonstrate the parameter values (or ranges) that lead to different levels of performance for accuracy and crosstalk. We also show that the optimization of accuracy and crosstalk is often driven by competing conditions, and thus, we perform a multi-objective optimization procedure and estimate the respective trade-off parameters. Finally, we present the effects from sensor shifts and evaluate the resulting increase in accuracy error. Our results and analysis can be used to facilitate the selection of parameters in future PSOG systems.

We introduce StoryFaces, a new composition and storytelling tool for children to explore the role of emotional expressions in children's narrative. StoryFaces invites children to record emotional expressions that become part of storybook illustrations. As children watch the story being told, they see their faces bring the story to life; then they can "go backstage" to play with the story by rearranging the videos and altering the story text. More experienced children can build an interactive ebook from the ground up, creating scenes, characters and expressive faces to craft personalized narratives. Our design rationale focuses on supporting children's exploration of emotional expression through their narrative play. Results with eighteen children ages 4-10 indicate that emotional expressions are inviting and motivating for children across this broad age range to engage in both reading and creating narrative. StoryFaces gave children's ephemeral facial expressions concrete forms with which they could manipulate, discuss, and think about the role of emotion in narratives. Our goal is to provoke new ideas about how pretend play with digital tools can empower young children in social-emotional narrative activities.

We introduce People in Books with FlashCam technology, a system that supports children and long-distance family members to act as characters in children's storybooks while they read stories together over a distance. By segmenting the video chat streams of the child and remote family member from their background surroundings, we create the illusion that the child and adult reader are immersed among the storybook illustrations. The illusion of inhabiting a shared story environment helps remote family members feel a sense of togetherness and encourages active reading behaviors for children ages three to five. People In Books is designed to fit into families' traditional reading practices, such as reading ebooks on couches or in bed via netbook or tablet computers. To accommodate this goal we implemented FlashCam, a computationally cost effective and physically small background subtraction system for mobile devices that allows users to move locations and change lighting conditions while they engage in background-subtracted video communications. A lab evaluation compared People in Books with a conventional remote reading application. Results show that People in Books motivates parents and children to be more performative readers and encourages open-ended play beyond the story, while creating a strong sense of togetherness.

Electric Agents is a cross-media game that presents new ways for children to actively engage with television content. In the game Manny, a member of the Pranksters, steals words out of the mouth of Hector, a member of The Electric Company team, and hides them to prevent the story from progressing. Children collaborate through a mobile augmented reality experience to find and collect the missing vocabulary words relevant to the show narrative. The players return the stolen words back to the show by "throwing" the words towards the television using their mobile devices. This blend of a narrative and a game strives to make educational television content more engaging and participatory while fostering collaborative play and use of specific vocabulary words.

We present I/O Stickers, adhesive sensors and actuators that children can use to handcraft personalized remote communication interfaces. By attaching I/O Stickers to special wirelessly connected greeting cards, children can invent ways to communicate with long-distance loved ones. Children decorate these cards with their choice of craft materials, creatively expressing themselves while making a functioning interface. The low-bandwidth connections -- simple actuators that change as the sensor stickers are manipulated -- leave room not only to design the look and function of the card, but also to decide how to interpret the information transmitted. We aim to empower children to implement ideas that would otherwise require advanced electronics knowledge. In addition, we hope to support creative learning about communication and to make keeping in touch playful and meaningful. In this paper, we describe the design of the I/O Stickers, analyze a variety of artifacts children have created, and explore future directions for the toolkit.

This paper outlines a series of experiments to develop asynchronous messaging systems for preschool aged children. Three unique systems build on a foundational design called Toaster, a jack-in-the box toy with embedded mobile phone that allows children to playfully take and share electronic media. Orange Toaster allows children to create and share self-portraits; Family Toast allows children to browse family photos with physical tokens, and shares their self-portrait reactions with remote family members; Play with Elmo allows children and distant adults to asynchronously share playful video messages. Observations with over 30 children suggest that asynchronous photographic or video messaging with very young children is possible. The results of these studies indicate specific guidelines including (1) children's UI's need to be playful and immediate (2) UI designs for children should create the "here and now" feel of real-time interaction, and (3) adults' UI's must provide emotionally meaningful feedback from children to engage adult users.

How might we build on the physical interactivity of children's play to help children communicate over a distance? Pokaboo is a networked toy for children ages 2--5 to physically play even when they are far apart. Envisioned almost like a low-frame rate video chat, the system combines physically-linked buttons with photo and audio communication. A child will press a button down to take their own photo, and their self-portrait will pop up on their partner's device. The device was tested with both photo sharing and video chat. Children were most engaged when the buttons were part of a mobile video chat, where one child could press a button down and see their partner's button pop up in front of their far-away playmate. When the playmate responded with a button press, their button would magically pop up in front of them, in a form of physical call-and-response. Pokaboo shows how networked toys can help children to form engaging connections through physical play over a distance.

StoryVisit allows children and long-distance adults to experience a sense of togetherness by reading children's story books together over a distance. StoryVisit combines video conferencing and connected books: remote grown-up and child readers can see and hear each other, and can also see and control the same e-book. We report on research with 61 families - over 200 users including parents, children and long-distance readers - who used StoryVisit in their homes with a long-distance reader for at least one reading session. In addition, we report qualitative findings regarding nineteen of the families who participated in telephone interviews and four families who were monitored and interviewed by researchers at home. Results show that connected e-book video chat sessions last about five times as long as the typical video chats reported in previous research on families with young children. Moreover, the addition of an animated character increased session lengths by another 50%. StoryVisit usage peaked for families with three year olds, showing that sustained distance interactions with very young children are possible if communication technologies incorporate joint activities that engage children and adults.

In this work, we introduce Interactive Rich Reading, a new enhanced book experience designed to run on smartphones and a tablet device. Interactive Rich Reading is characterized by a video-based conversational agent that asks questions or makes comments about the current page and is specifically designed to promote engagement with the contents of children's books. We use video compositing techniques to overlay the conversational agent directly over the book contents, creating a magical experience for children by bringing the book to life. We describe technical issues related to enabling this experience on mobile platforms for easier adoption of this technique by other researchers and practitioners.

Long-distance families are increasingly staying connected with free video conferencing tools. However research has highlighted a need for shared activities for long-distance family communication. While video technology is reportedly superior to audio-only tools for children under age 7, the tools themselves are not designed to accommodate children's or families' needs. This paper introduces four design explorations of shared play activities over video conferencing that support family togetherness between children and remote adult family members. We build on research in CSCW and child development to create opportunities for silliness and open-ended play between adults and young children. Our goal is to scaffold interaction across distance and generations.

What if children's make-believe characters could keep in touch when the children were apart? We propose a novel concept for children's use of technology through imagination play: user interfaces designed to be used by children's character toys rather than directly by the children ("doll-computer interfaces"). We apply this model to the challenge of remote communication for children with an enhanced dollhouse containing small-scale interfaces for the dolls with a variety of fully functional multimodal communication functions. Using this interface as a technology probe, we explore a variety of design decisions with remote pairs of children. Our preliminary results suggest that toy-perspective and manipulable toy elements are particularly helpful in supporting play and successful use of communication technologies, while the "true-to-life" toy aspects are sensitive to individual frames of reference and more flexible interfaces that still fit within the toy context lead to creative communication strategies. We found that different communication channels offered interesting tradeoffs between uninterrupted play and rich verbal description. We also learned that the concept appeals to a wide age range but that the youngest children may need additional scaffolding for successful remote play.

We introduce Family Story Play, a system that supports grandparents to read books together with their grandchildren over the Internet. Family Story Play is designed to improve communication across generations and over a distance, and to support parents and grandparents in fostering the literacy development of young children. The interface encourages active child participation in the book reading experience by combining a paper book, a sensor-enhanced frame, video conferencing technology, and video content of a Sesame Street Muppet (Elmo). Results with users indicate that Family Story Play improves child engagement in long-distance communication and increases the quality of interaction between young children and distant grandparents. Additionally, Family Story Play encourages dialogic reading styles that are linked with literacy development. Ultimately, reading with Family Story Play becomes a creative shared activity that suggests a new kind of collaborative story telling.

In this paper we introduce the TessalTable, a collaborative play system for learning about tessellations and symmetry through augmented pattern blocks. Children use tiles to "pick up" a piece of an image or video. The tiles act as containers for visual content which can be arranged and rearranged anywhere on the application surface. The tile-based controls allow for simultaneous multi-user input. A preliminary study found that children understand and engage with the interface. The ability to arrange and rearrange dynamic images invites users to explore geometric patterns and connected motion.

We interviewed and observed families in their homes to understand how they communicate across generations and across distances. The phone is still the most common way for keeping children in touch with distant relatives. However, many children can't talk on the phone by themselves until 7 or 8 years old. This paper examines the challenges children have with phone conversations, and looks at how families are currently working around these issues. These findings can help inform the design of future family communications technologies.

Based on ten years' experience developing interactive camera/projector systems for public science and culture exhibits, we define a distinct form of augmented reality focused on social interaction: social immersive media. Our work abandons GUI metaphors and builds on the language of cinema, casting users as actors within simulated narrative models. We articulate philosophical goals, design principles, and interaction techniques that create strong emotional responses and social engagement through visceral interaction. We describe approaches to clearly communicate cultural and scientific ideas through the medium. And we demonstrate how practitioners can design interactions that promote specific social behaviors in users.

The Sound of Touch is a new tool for real-time capture and sensitive physical stimulation of sound samples using digital convolution. Our hand-held wand can be used to (1) record sound, then (2) play back the recording by brushing, scraping, striking or otherwise physically manipulating the wand against physical objects. During playback, the recorded sound is continuously filtered by the acoustic interaction of the wand and the material being touched. The Sound of Touch enables a physical and continuous sculpting of sound that is typical of acoustic musical instruments and interactions with natural objects and materials, but not available in GUI-based tools or most electronic music instruments. This paper reports the design of the system and observations of thousands of users interacting with it in an exhibition format. Preliminary user feedback suggests future applications to foley, professional sound design, and musical performance.

What issues arise when designing and deploying tangibles for learning in long term evaluations? This paper reports on a series of studies in which the Topobo system, a 3D tangible construction kit with the ability to record and playback motion, was provided to educators and designers to use over extended periods of time in the context of their day-to-day work. Tangibles for learning - like all educational materials - must be evaluated in relation both to the student and the teacher, but most studies of tangibles for learning focus on the student as user. Here, we focus on the conception of the educator, and their use of the tangible interface in the absence of an inventor or HCI researcher. The results of this study identify design and pedagogical issues that arise in response to distribution of a tangible for learning in different educational environments.

We present Remix and Robo, new composition and performance based tools for robotics control. Remix is a tangible interface used to sample, organize and manipulate gesturally-recorded robotic motions. Robo is a modified game controller used to capture robotic motions, adjust global motion parameters and execute motion recordings in real-time. Children use Remix and Robo to engage in (1) character design and (2) competitive endeavors with Topobo, a constructive assembly system with kinetic memory.

We introduce Jabberstamp, the first tool that allows children to synthesize their drawings and voices. To use Jabberstamp, children create drawings, collages or paintings on normal paper. They press a special rubber stamp onto the page to record sounds into their drawings. When children touch the marks of the stamp with a small trumpet, they can hear the sounds playback, retelling the stories they created.

Digital Manipulatives embed computation in familiar children's toys and provide means for children to design behavior. Some systems use "record and play" as a form of programming by demonstration that is intuitive and easy to learn. With others, children write symbolic programs with a GUI and download them into a toy, an approach that is conceptually extensible, but is inconsistent with the physicality of educational manipulatives. The challenge we address is to create a tangible interface that can retain the immediacy and emotional engagement of "record and play" and incorporate a mechanism for real time and direct modulation of behavior during program execution.We introduce the Backpacks, modular physical components that children can incorporate into robotic creations to modulate frequency, amplitude, phase and orientation of motion recordings. Using Backpacks, children can investigate basic kinematic principles that underly why their specific creations exhibit the specific behaviors they observe. We demonstrate that Backpacks make tangible some of the benefits of symbolic abstraction, and introduce sensors, feedback and behavior modulation to the record and play paradigm. Through our review of user studies with children ages 6-15, we argue that Backpacks extend the conceptual limits of record and play with an interface that is consistent with both the physicality of educational manipulatives and the local-global systems dynamics that are characteristic of complex robots.

We introduce Topobo, a 3D constructive assembly system embedded with kinetic memory, the ability to record and playback physical motion. Unique among modeling systems is Topobo's coincident physical input and output behaviors. By snapping together a combination of Passive (static) and Active (motorized) components, people can quickly assemble dynamic biomorphic forms like animals and skeletons with Topobo,animate those forms by pushing, pulling, and twisting them, and observe the system repeatedly play back those motions. For example, a dog can be constructed and then taught to gesture and walk by twisting its body and legs. The dog will then repeat those movements and walk repeatedly.Our evaluation of Topobo in classrooms with children ages 5-13 suggests that children develop affective relationships with Topobo creations and that their experimentation with Topobo allows them to learn about movement and animal locomotion through comparisons of their creations to their own bodies. Eighth grade science students' abilities to quickly develop various types of walking robots suggests that a tangible interface can support understanding how balance, leverage and gravity affect moving structures because the interface itself responds to the forces of nature that constrain such systems.