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 chine for this information. The best way to guide the human into supplying this information, while avoiding a tedious and long series of direct queries, is a largely unstudied area. Also, since the structure of the knowledge involved in the dialogue differs considerably between the human and machine, it will be necessary to map the initial internal "need to know" requests perceived by the machine into the general flow of the dialogue in a human-oriented way.

6.3.2 Machine Recognition and Understanding of Spoken Language Recognition and understanding of fluent spoken language add further complexity to that of keyed language/ phoneme ambiguity. In noise-free environments where restricted vocabularies are involved, it is possible to achieve relatively high recognition accuracy though at present not in real-time. In more realistic operating scenarios, oral fluency and recognition divorced from semantic understanding is not likely to succeed. The critical need is the coupling of a linguistic understanding system to the spoken natural language recognition process. Thus the progress in speech recognition will depend upon that in keyed natural language understanding. Early applications have involved single word control directives for machinery that acts upon the physical world, using commands like "stop," "lower," "focus," etc. Some commercial equipment is available for simple sentences, but these require commands to be selected from a small predetermined set and necessitate machine training for each individual user.

6.3.3 Machine Generation of Speech At the present time mechanical devices can generate artificial-sounding but easily understood (by humans) spoken output. Thus the physical aspects of speech generation are ready for applications, although some additional aesthetics-oriented technology work would be desirable. (The more important aspects of deciding what to say and how to phrase it were covered in the foregoing discussion of keyed natural language.)

6.3. 4 Visual and Other Communication Some motor-oriented transfer of information from humans to machines already has found limited application. Light pens and joysticks are rather common, and some detection of head-eye position has been employed for target acquisition. Graphics input/output is also an active research area, and three-dimensional graphical/pictorial interaction is likely to prove useful. An interesting alternative approach in communicating information to robot systems is called "show and tell." In this method a human physically manipulates an iconic model of the real environment in which the robot is to act. The robot observes this action, perhaps receiving some simple coordinated information spoken by the human operator as he performs the model actions, then duplicates the actions in the real environment. The distinctions between show and tell and typical teleoperator modes of operation are: • Show and tell does not assume real-time action of the robot with the human instruction. • For show and tell, the robot has the time to analyze the overall plan, ask questions and generally form an optimal course of action by communicating with the human. • The fidelity of the robot actions to the human exampie can vary in significant useful ways, allowing the robot to optimize the task in a manner alien to human thinking. • The show and tell task can be constructed piecemeal, thus allowing a task to be described to the machine which requires many simultaneous and coordinated events, or which requires input from teams of human operators which is then chained together into a single more complex task description. Show and tell permits a high degree of cooperative problem-solving and reasoning about actions between humans and machines. This novel technique probably has an important functional role to play somewhere between autonomous robots and pure teleoperation.

6.3.5 Recommendations The team recommendations to NASA regarding directed research and development in the field of natural languages and other man-machine dialogue are as follows. Natural language and man-machine dialogue. Theoretical work in keyed and spoken natural language for managing restricted domain databases will proceed with NASA involvement. The impact of such systems is widely recognized, and much research is in progress. In applications, DOD is already involved in funding research whose results will probably be directly applicable to NASA database interactions in the immediate future. It is recommended that NASA now make plans to initiate implementation of systems using keyed natural language for internal use within NASA. Such implementation not only will provide useful production tools for NASA, but also will generate the in-house experience necessary to provide these techniques to outside users of space-acquired data as in the IESIS mission. More sophisticated uses of natural language, such as in directing almost autonomous robots in tasks like space constructions hould best u died