The AirBook:force-free interaction with dynamic textin an assistive reading deviceMaribeth Back and Margaret H. SzymanskiXerox PARC3333 Coyote Hill RoadPalo Alto, CA USA+1 650 812 4726back,[email protected] describe a prototype of the AirBook, an assistivereading device that combines dynamic text (especiallyRSVP, that is, rapid serial visual presentation) with force-free capacitive field sensors to create a simple, easilycontrolled assistive reading device. This reader is designedto assist people with visual disabilities (like dyslexia, lossof fine motor control or loss of contrast sensitivity) bygiving them more control over font size and contrast. It’salso for people with upper-body disabilities, lack of finemuscle control, or severe arthritis, all of which can makethe reading of standard paper books difficult. The force-free sensor system can be adjusted for large-scale motion orfor tiny ranges of movement, and requires no pressure orfiddling with physical objects. The sensors read theproximity of a human limb, and adjust parameters on thetext accordingly. For example, the reading device can becontrolled with the motion of one finger if necessary, oradjusted to read the motion of an entire arm or leg.KeywordsDynamic text, kinetic text, assisted reading, speed reading,interaction design, RSVP, interaction metaphors ,navigation, capacitive field sensors, force-free interaction.INTRODUCTIONOur work explores new ways of experiencing text: newgenres, new styles of interaction, and unusual media. Onesuch project was the design of a set of reading instrumentsfor an exhibit at the San Jose Tech Museum of Innovationentitled “XFR: Experiments in the Future of Reading.” [1]Our goal for the XFR exhibit, which drew over 250,000visitors in six months, was to associate a sense ofexcitement, fun, and personal control with reading.Visitor responses to the exhibit often focused on possibleassistive uses of these new technologies and led us toexplore the design of an assitistive reading instrument TheAirBook is an adaptation of a device called Speeder Readerwhich was part of the XFR exhibit. The AirBookemphasizes personal control; it is built upon the idea thatboth text and the device that is used to read it should bedesigned for the convenience of the reader, not constrainedby issues like limited page space (which leads to smallfonts) or the necessity to hold a book and turn its pages(which some people find difficult).Many assisted reading devices and systems already exist.[2] Some focus on text-to-speech systems, some areelaborate robotic devices for manipulating real books, andothers are software display systems. However, we foundnone that combine ease of physical control withadjustments for visual compatibility in the way that theAirBook does. Simplicity and relatively low cost are otherattractive factors in this design.DescriptionThe AirBook consists of a computer, a monitor and atabletop interface which is two leather-covered sensorelectrode plates (copper foil plates about four inchessquare), mounted at a comfortable angle (about 30degrees). The plates are connected to capacitive fieldsensors, which can track the proximity of anythingconductive, including human hands and fingers. Althoughin this prototype the plates are surface-mounted to a table,they can also be mobile pads or small boxes that can beplaced wherever is most convenient.A reader sits at a table and controls the text as it appears onAirBook’s computer screen by sliding her arms or handsalong the stable table-mounted surface, until a comfortablereading speed is reached. Then no more motion is required,until the reader has finished. The range of motion anddegree of control required is adjustable for the needs ofeach individual. Content can be anything that is parsableinto XML format, including books, papers, or the Web.Dynamic text for assistive systemsPeople read printed words on a page in “saccadic jumps,” aseries of somewhat erratic eye motions around a page.Saccadic jumps enable people to read in a conventional leftto right, top to bottom sweep [5]. Those who cannot makesaccadic jumps properly often experience difficultyreading. RSVP (rapid serial visual presentation) is a kindof dynamic typography where words or short phrasesappear in sequence, centered on a screen. As the wordscontinually flash in one spot, the reader does not have tomove his or her eyes, thus minimizing the saccadic jumpsand eliminating the time needed to move and refocus theeyes on standard printed materials. With this protocolpeople have been known to increase their reading speed upto 2000 words per minute (an average proficient reader canread about 400-600 words per minute). RSVP wasinvestigated in the 1980s as a presentation protocol for text[3] and has been used in several products as a speedreading technology. Neurologists and perceptualpsychologists among others have used it as a research tool[4, 5]. Appropriate typographical and color choices also aidin comprehension and speed.Fig. 1. The AirBook. Sketch of table model. Sensors canalso be mobile pads for placing on chair arms, beds, etc.Navigation and control with force-free sensorsOne problem with RSVP text is how to browse it. Howdoes one find different sections of content, play them at anappropriate speed, and replay them at will? In the AirBook(Fig. 1) the RSVP text is visible in a 3” by 12” rectangularwindow onscreen; a system control window is visiblebelow it. The physical interface provides two force-freesensor plates, which read simple proximity achieved bysliding one’s hand along a tabletop (or waving it above thesensor in mid-air; hence “AirBook”). Thus, readers cancontrol various system parameters or navigate to differentstreams of text by moving their hands, which are supportedby the tabletop. One sensor gives the user control over thespeed of the text being displayed. The other sensor allowsa higher-level set of choices, such as moving the window toa different “lane” of text, in a sideways motion. Thiscontrol sensor offers the following parameters: textselection; skipping backwards or forwards to specificpoints in the text; starting over from the beginning; orsetting a bookmark. A reader can also adjust font size,style, and color contrast with this control.TechnologyForce-free sensors are sensors that do not require physicalmanipulation. In this application we use capacitive fieldsensors from Quantum Research Labs, the QT110. [6] Thesensor