Encyclopedia of Computer Science and Technology

haptic interfaces 221Currently, handwriting recognition is used mainly inniche applications, such as collecting signatures for deliveryservices or filling out “electronic forms” in applicationswhere the user must be mobile and relatively hands-free(such as law enforcement).Further ReadingCrooks, Clayton E. II. Developing Tablet PC Applications. Hingam,Mass.: Charles River Media, 2003.“Handwriting Recognition.” TechRepublic Resources. Availableonline. URL: http://search.techrepublic.com.com/search/handwriting+recognition.html. Accessed August 6, 2007.Liu, Zhi-Qiang, Jin-Hai Cai, and Richard Buse. Handwriting Recognition:Soft Computing and Probabilistic Approaches. New York:Springer, 2003.Matthews, Craig Forrest. Absolute Beginner’s Guide to Tablet PCs.Indianapolis: Que, 2003.Taylor, Paul. “Cast Off Your Keyboard.” Financial Times/FT.comAugust 2, 2007. Available online. URL: http://www.ft.com/cms/s/04546598-410d-11dc-8f37-0000779fd2ac.html.Accessed August 6, 2007.Van West, Jeff. “Using Tablet PC: Handwriting Recognition 101.”Available online. URL: http://www.microsoft.com/windowsxp/using/tabletpc/getstarted/vanwest_03may28hanrec.mspx.Accessed August 6, 2007.Zimmerman, W. Frederick. Complete Guide to OneNote. Berkeley,Calif.: Apress, 2003.One approach to handwriting recognition involves the extraction ofa stroke pattern and its comparison to a database of templates representingvarious letters and symbols. Ultimately the correspondingASCII character is determined and stored.because accuracy often requires that users write very carefullyand consistently or (as in the case of the Palm) evenreplace their usual letter strokes with simplified alternativesthat the computer can more easily recognize. If the user isallowed to use normal strokes, the system must be gradually“trained” by the user giving writing samples and confirmingthe system’s guess about the letters. As the softwarebecomes more adaptable and processing power increases(allowing more sophisticated algorithms or larger neuralnetworks to be practical) users will be able to write morenaturally and systems will gain more consumer acceptance.(One step in this direction is the Tablet PC, a notepad-sizedcomputer with a digitizer tablet and a stylus and handwritingrecognitions software, included in Windows XP andexpanded in Windows Vista. Programs such as MicrosoftOneNote use handwriting recognition to allow users toincorporate handwritten text into notes that can be organizedand quickly retrieved.)haptic interfacesMost interfaces between users and computer systems involvethe equivalent of switches—keyboard keys or mouse buttons.These interfaces cannot respond to degrees of pressure(for an exception, see graphics tablet). Further, thereis no feedback returned to the user through the interfacedevice—the key or mouse does not “push back.”Haptic (from the Greek word for “touch”) interfaces aredifferent in that they do register the pressure and motion oftouch, and they often provide touch feedback as well.Force-feedback systems use movement of the controlas a way to provide feedback to the operator. A commonexample is the control stick in an aircraft that begins tovibrate as the aircraft approaches a stall (where it wouldlose control). This provides immediate feedback to the pilotusing the device by which he or she is already controllingthe plane.More sophisticated forms of force feedback are used inremote-controlled devices for manipulation or exploration.The first application was developed in the 1950s for handlingradioactive materials. Today a combination of positionand movement sensing and force feedback can be usedwith special gloves to enable users to grasp and heft 3Dvirtual objects while getting a sense of their weight, shape,and even texture.In games, haptic joysticks and other controls such assteering wheels can provide sensations such as resistance toa car’s turn or the sensation of a bat hitting a ball. The NintendoWii game console comes with a controller that tracksthe direction and speed of its movement along with a set ofsimple but engrossing sports games to show its capabilities.Some emerging or near-future uses of haptic technologyinclude: