Design and evaluation of interactive instruction as communicative dialogue

Throughout history hearing people have been puzzled about the difficulty to communicate with deafpeople; a puzzlementperhaps strengthened by the fact that hearing is only one of the human sensory faculties. Apparently loss of hearing affects human communication far more than any other sensory impairment. On analyzing the communication process in more detail one finds that it is made possible by a large numberofconditions thatall have to be satisfied in order to proceed successfully. It appears to be inherently uncertain, it requires a great deal of redundancy, and makes use of an, often implicit, protocol. On closer analysis it turns out that the process of manual signing embodies the same communicative principles as spoken communication; even if a number of features are different as a consequence of the visual display. Inasmuch as the development of sign language seems to parallel that of spoken language in many ways, sign language qualifies undoubt­edly as a language in its own right. Interactive instruction can be considered to be a special kind ofcommunication with dialogue rules that are in many ways different from those in other types of person-to-person communication. Some ofthese are beneficia! for interactive instructional systems, but a persistent problem is still how to obtain informative feedback, and how to deal with it in the ongoing interaction. One example is the question of how to provide spoken instances ofletters in words, or words in a text for hearing impaired ordeaf children when they try learning to rcad. Alphabetic script has many problems for those who do not have the same audible representation of language as hearing people. Current insight in communication processes suggests that one should abstain from strong statements on education for deaf people and concen­trate instead on evaluation of the intelligibility and comprehensibility of the instructional dialogue.