Simply making speech recognition available with machines,however, does not necessarily make it immediately useful; it willhave to be interfaced properly with the other modalities so that itappears seamless to the user (Martin et al., 1996). (Severalvendors have been shipping speech recognition capabilities withpersonal computers, but there is little evidence of wide usage.)Optimism for general use of speech technologies comes from thefacts that performance levels are continuing to improve and thatmany applications do not require large vocabulary sizes. However,applications must be designed to take into account the fact thatrecognition errors will occur, either by allowing the user tocorrect errors or by designing additional error correctionmechanisms, such as proper inclusion of human-machine dialoguecapabilities. These include the ability to deal with issues such ashow to phrase a system prompt, how to determine if a recognitionerror has occurred, and how to engage in conversational repair ifsuch a determination is made. Other speech integration issuesinclude habitability (the ability of a user to stay within thesystem's vocabulary most of the time), portability (the ease withwhich a speech recognition system can be ported to a new domain),and user experience (different users, depending on theirexperience, may require different types of interaction).
Rimé and Schiaratura (1991) characterize several classesof gesture. Symbolic gestures are conventional,context-independent, and typically unambiguous expressions (e.g.,\"OK\" or peace sign). In contrast, deictic gestures are pointers toentities, analogous to natural language deixis (e.g., \"this notthat\"). Iconic gestures are used to display objects, spatialrelations, and actions (e.g., illustrating the orientation of twocars at an accident). Finally, pantomimic gestures display aninvisible object or tool (e.g., making a fist and moving toindicate a hammer). Gestural languages exist as well. These includesign languages and signing systems for use in environments wherealternative communication is difficult. Early experience with gloveinterfaces indicates that some users have difficulty rememberingthe gesture equivalents to commands (Herndon et al., 1994).
section-is only part of the input/output requirement for ECIs.Integration of these technologies into systems that use multiplecommunications modalities simultaneously-multimodal systems-canimprove people's performance. (These ideas are discussed in moredetail in Chapter 6.) Integration can also ensure that at least onemechanism is available for every person and situation, independentof temporary and/or permanent constraints on their physical andcognitive abilities. Virtual reality involves the integration ofmultiple input and output technologies into an immersive experiencethat, ideally, will permit people to interact with systems asnaturally as they do with real-world places and objects.
All of these features can be added to a standard multimediatouchscreen kiosk without adding any hardware beyond a singleswitch and without altering the interface experienced byindividuals who do not have disabilities. By adding interfaceenhancements such as these, it is possible to create a singlepublic kiosk that looks and operates like any traditionaltouchscreen kiosk but is also accessible and usable by individualswho cannot read, who have low vision, who are blind, who arehearing impaired, who are deaf, who have physical disabilities, whoare paralyzed, or who are deaf and blind. Kiosks with flexibleuser-configurable interfaces have been distributed in Minnesota(including the Mall of America), Washington State, and otherstates.
Because ECIs must work in a networked environment, interfacedesign involves choices that depend on the performance of networkaccess and network-based services and features. What ramificationsdoes connection to networks have for ECIs This question isrelevant because a user interface for any networked application ismuch more than the immediate set of controls, transducers, anddisplays that face the user. It is the entire experience that theuser has, including the following:
22. Many users of today's Internet telephony services experiencea long delay, sometimes of the order of a second, in transmission,actually due more to buffering in the user's computer to smooth outarriving packets. 153554b96e