METHOD AND APPARATUS FOR EXECUTING A HUMAN-MACHINE DIALOGUE IN THE FORM OF TWO-SIDED SPEECH FOR EXECUTING A MACHINE-CONTROLLED DIALOGUE FOR APPOINTMENT RESERVATION

Abstract: A method for executing a machine-controlled appointment reservation dialogue, first receives an external remote access call that is interrogated for ascertaining that a reservation appointment is requested. If positive, the reservation appointment so requested is interactively checked versus an appointment schedule. If positive, a feasible reservation item is entered into an appointment memory. In particular, the method is based on executing a bidirectional and negotiative human-machine speech dialogue for the ascertaining and checking, and for reservation entering into a digital appointement memory.

Description: Method and Apparatus for Executing a Human-Machine Dialogue in the Form of Two-sided Speech for Executing a Machine Controlled Dialogue for Appointment Reservation. BACKGROUND OF THE INVENTION The invention relates to a method for executing a machine-controlled appointment reservation dialogue, comprising the steps of; receiving an electronic remote access call; - interrogating said call for ascertaining that a reservation appointment is requested; upon a positive result of said ascertaining, interactively checking the reservation appointment so requested versus an appointment schedule; upon a positive result of said checking, entering a feasible reservation item into an appointment memory. Such appointment reservation methods can be useful for professional persons that render person-to-person services, such as medical doctors, although the invention can be used in many other situations where appointments must be reserved. A method according to the preamble has been disclosed in United States Patent 4,783,800. The known method is based on outputting speech messages by a central machine, which messages instruct a user person to enter user wishes for an appointment by means of telephone dialling. Such an approach has been experienced by many ordinary user persons as being utterly user-unfriendly, for example in that user wishes must be presented as being embodied in a strictly prescribed format. Also, the known method is extremely prone to dialling errors by a user, which may often lead to reservation errors that cannot be recovered by the system. SUMMARY TO THE INVENTION Accordingly, amongst other things, it is an object of the present invention to provide a method according to the preamble that allows a user to enter messages in a nearly free format, while remaining nevertheless robust to a high degree against user-induced errors. Now, according to one of its aspects, the invention provides a method based on executing a bidirectional and negotiative human-machine dialogue in speech for said ascertaining and said checking, for thereupon entering said reservation item into a digital appointment memory. Present-day speech recognition can be supplemented by speech understanding, so that the key items of a message can be extracted, given the known range of the messages that should be recognized Completing the operation with the entering in a digital memory allows quick information retrieval that may be necessary under various types of emergency situations. Advantageously, said negotiative dialogue is effective for detecting a reservation unfeasibihty, for thereupon transferring said dialogue to a secondary human operator for further said checking. In the rare cases that the machine has to give up, the transfer to an operator person caters for situations experienced as extremely difficult. These can be caused by problems on several levels; the user speech cannot be understood by the machine, the user cannot answer questions in a sufficiently straightforward manner, the user wants a service that the machine is not authorized to give, or rather, the service is outright impossible. The invention also relates to a method for executing the method according to the above. In particular, the apparatus may have memory means for in conjunction with an entered reservation item, storing a user person message. This allows the service provider to take particular advance measures, if wished by the customer or appointee. Further advantageous aspects of the invention are recited in dependent Claims. BRIEF DESCRIPTION OF THE DRAWING These and other aspects and advantages ot the invention will be discussed more in detail hereinafter with reference to the disclosure of preferred embodiments, and more in particular with reference to the appended Figures that show; Figure 1 , an overall block diagram of an inventive system; Figure 2, a procedure flowchart; Figure 3, various appointment diagrams; Figure 4, an exemplary storage format. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 is an overall block diagram of a system according to the invention. Item 20 represents the interconnection to a public telephone net. Block 24 represents a standard interface facility to this net, which tor an analog net allows to receive and sample speech, as well as to output analog speech on the net. If the net is digital, facilities are provided for interfacing to the net in a comparable manner. Block 26 is a subsystem for recognizing received speech, as well as for outputting to the customer speech of prescribed content. By itself, speech recognition has been disclosed in various documents, such as EP 417 854, corresponding to US Patent 5,228, 1 10 (PHD 89158), EP 533 259, corresponding to US Serial No. 08/425,304 (PHD 91 136), EP 533 261 . corresponding to US Serial No. 08/312,495 (PHD 91 137), EP 533 260, corresponding to US Serial No. 08/563,853 (PHD 91 138), EP 614 172, corresponding to US Serial No. 08/203, 105 (PHD 93034), EP 752 129, corresponding to US Serial No. 08/587, 190 (PHN 15167), all to the assignee of the present application. Speech generation has been disclosed in various documents, such as EP 95202202.8, corresponding to US Serial No 08/696,431 (PHN 15408), EP 96200015.4, corresponding to US Serial No ... (PHN 15641 ), all to the assignee of the present application. Block 28 is a dialogue control subsystem that undertakes to understand the speech entries received, given the intention of the speech entries to make an appointment reservation in the reservation memory 30. Block 28 also produces speech messages for outputting on interface 20 to elicit from a user such informations that are further necessary. In this way a bidirectional speech dialogue with the user can be undertaken. Block 30 is a reservation memory which is organized to store appointment reservations that each cover a time slot that may be of uniform or variable size, so that the slot in question can be -free- or -reserved-, the latter state blocking entry of a further appointment reservation for that slot, except for overruling by a system manager. The storage format will be discussed hereinafter. Block 36 is a user keyboard that may be standard alphanumerical, although special function keys for the application may be provided as well. This keyboard can be used for manual entering of reservations by an operator, for affirming or rejecting reservations made independently by the system, and by the system operator to govern control on a higher level, such as in case of emergency situations. Block 34 is a standard display screen for showing the contents of the reservation memory 30, or more generally providing informations regarding the system. Item 32 is a local communication system interconnecting the items that can be usually directly controlled by the operator of the system. Item 38 is a speech memory that may for each reservation appointment store an amount of user speech, either after digitizing and recognition thereof or in the way as received. In the first case the storage is as a string of speech codes that in a straightforward matter may be reconverted into audible speech. In the second case, a special output mechanism must be provided that has been symbolized by means of speech output block 40. Analog speech transfer between memory 38 and block 40 has been ignored for clarity. Block 40 may be bidirectionally operative, so that a human operator can maintain a dialogue in speech with an actual user person. Figure 2 is a procedure flowchart, that centers on the ascertaining and checking of the appointment request. In another environment, a transaction system that allows for ascertaining a complex wish of a user person for particular information through bidirectional speech, in combination with a limited set of possibilities has been disclosed in European Patent Application 96201717.4, corresponding US Application Serial No (PHN 15871) to the present assignee and herein being incorporated by reference. In particular, slot filler items are ascertained by the reference by means of graph building wherein the graph nodes represent slot fillers for defining the information request. In contradistinction to the earlier system, the present invention provides exclusivity for the reservations, in that each reservation made thereby precludes the subsequent, making of an identical other reservation. Herein, the system itself may define that two or more parallel reservations are allowed at certain times. These parallel reservations are then considered by the reservation system as being mutually unique. In the flow chart, block 50 represents the start, that is activated through a remote call from a user person by telephone or by another electronic medium. In block 52, the system produces an introductory speech message. In block 54, the system asks for a user to present an appointment reservation request, such as by asking "at what day and time do you want an appointment reservation'' " In block 56, a during a certain tune the system listens for a received speech message, but if nothing is received, in block 58 a count is accumulated. First, the system then reverts to block 54, for repeating the above questioning, possibly in a somewhat different formulation. If the number of repetitions has risen to, for example, three, the dialogue is transferred to a human operator in block 60, who handles the call further. If in block 56, a speech message is received, the recognition and subsequent understanding is undertaken in block 62. In block 64, it is detected whether some relevant information could be extracted, such as a time-of-day, a day-of-week, a date, or some other relevant information. If this is not the case, the system reverts to block 58, and proceeds as explained above. If some relevant information was found, in block 68 it is detected whether enough information has now been received, and if not, the system reverts to block 54, to ask for the remaining information. In particular, the system may allow for emergency requests, for example through entering a password. Alternatively, a recognized emergency call is directly transferred to a human operator. The appointment reservation request may be for a particular weekday, such as Monday; it may be for particular clock times that can be single- bounded (before ten o'clock) or double-bounded (between eight and nine o'clock). Also, combinations of the above are feasible, such as "Thursday afternoon". If the request is complete, it is checked in block 68 for allowability, for example, in that the requested interval as recorded in the memory 30 is still free indeed. If such is possible, the appointment reservation is presented to the user in the form of speech once more, such as: "You want a reservation appointment for Thursday, March 12, at 10.15 hours in the morning" , which must then be acknowledged by the user in speech (block 69 that presumes a positive reaction from the user person; if the reaction is negative, the procedure follows according to the negative output of block 72). If the acknowledge is positive, the appointment reservation is entered in the reservation memory. Subsequently, the user person is asked whether any special speech message must be recorded by the system (block 74). If this recording is finished, or deemed superfluous by the customer (block 78), the operation is accomplished, and the system takes leave from the customer with an appropriate goodbye message in speech (block 80). If, in block 68, the requested reservation is not possible for some organizational reason, in block 70 an alternative is proposed by the system in speech, which alternative is believed to correspond most closely to the wishes of the customer. This may pertain to the earliest possibility after the requested time, to the same clock time on another day, or according to some other policy, taking into account the specifications given in the user request. In block 72 the customer is asked in speech whether this proposal is deemed acceptable. If yes, the system goes to block 74. If no, in block 76 the number of such proposals is counted. If not more than three, a subsequent proposal is done in speech in block 70. If already three proposals had been made, the system reverts to block 60 for allowing operator intervention. Figure 3 shows various appointment diagrams. Trace 3A indicates time. Trace 3B indicates clock time in a linear manner, together with a series of quarter-hour time slots that each may accommodate one appointment reservation. As shown, four such reservations have indeed been made. Trace 3C indicates in a similar manner that reservations can occupy half an hour, whereas two such reservations may be coexistent at any time. Many other patterns may be necessary. The lengths of appointments may be non-uniform, pauses may be interspersed. As to the reservation requests themselves, these may be standard, or the customer may indicate the interval that is necessary. Preferably, customers are only allowed to make standard length appointments with the system, whereas non-standard appointments would need intervention by a human operator. Trace 3D shows occurrence of a time overrun in that appointment 38 takes the time interval necessary for two successive appointments. The system then may undertake to correct in a selfrehant manner, in that first, all appointments are effectively delayed by one quarter ot an hour, until the cancelling of appointment reservation at time interval 40 is deemed feasible The cancelling message, and if feasible, the delay incurred by the others, is then communicated to the customers by an automatic dialling subsystem in the system according to the invention, tor after each dialling operation communicating in speech an appropriate regrettory message to the customer in question. This automatic dialling system may be executed by block 31 in Figure 1 that may operate as a governing authority. For simplicity, the dialling facility by itself has been considered standard and has not been shown separately. To some degree, the dialogue in effecting the delay may be the mirror of the dialogue of Figure 2 Alternatively, the automatic dialling may be effected by the system, whereas the rescheduling of the appointment is under operator control Subsequent to time interval 40, the system proceeds in the manner originally planned. Figure 4 is an exemplary storage format ot an appointment reservation. First, item ID is the reservation identifier. Item START is the beginning time, inclusive of the date. Item STOP is the termination instant ot the reservation Item PERSON identifies the person for whom, or by whom the reservation was made. If these can be different and such would be relevant for the appointment, the format should accommodate the entering of two person's names. ATTRIB 1 ,2 are two fields tor attributes These can store the type of appointment, the manner of payment tor the service, or various other relevant information. The fields POINTER 1 , 2 can contain pointers to various other locations, such as a pointer to the speech memory 38, and a location to other relevant data, such as X-Ray photographs accessible by the system. The field RESERVE can be left tor future extensions The writing in the appointment reservation memory can be done by the system as explained. In addition thereto, the operator can be authorized to write in similar manner, tor example to block certain periods against automatic reservations, or to overrule or cancel appointment reservations already made. Also, the operator may be allowed to seltreliantly enter speech comments into the speech memory as pertaining to a particular appointment reservation, or rather, to enter notes into particular format fields.

Claims: CLAIMS: 1. A method for executing a machine-controlled appointment reservation dialogue, comprising the steps of: receiving an electronic remote access call; interrogating said call for ascertaining thai a reservation appointment is requested; upon a positive result of said ascertaining, interactively checking the reservation appointment so requested versus an appointment schedule; upon a positive result of said checking, entering a feasible reservation item into an appointment memory, characterized in that said method is based on executing a bidirectional and negotiative human- machine dialogue in speech for said ascertaining and said checking, for thereupon entering said reservation item into a digital appointment memory. 2. A method as claimed in Claim 1 , wherein said negotiative dialogue is effective for detecting a reservation unfeasibility, for thereupon transferring said dialogue to a secondary human operator for further said checking. 3. A method as claimed in Claims 1 or 2, whilst providing for proposing one or more reservation items by said machine. 4. A method as claimed in Claims 1 , 2 or 3, wherein aid dialogue allows for checking emergency requests, single-bounded and double-bounded clock time requests, day-of-week requests, and combinations thereof. 5. An apparatus for executing the method as claimed in any of Claims 1 to 4. 6. An apparatus as claimed in Claim 5 , and allowing operator-sided writing into said memory. 7. An apparatus as claimed in claim 6, and allowing operator-sided appointment cancelling in said memory, and having means for thereupon executing remote communicating said cancelling to one or more appropriate user stations. 8. An apparatus as claimed in Claims 5, 6 or 7, and having speech memory means for in conjunction with an entered reservation item, storing a user person speech message.

Inventors: OERDER MARTIN, OERDER, MARTIN
Applicants: PHILIPS ELECTRONICS NV, PHILIPS NORDEN AB, PHILIPS PATENTVERWALTUNG, PHILIPS ELECTRONICS N.V., PHILIPS PATENTVERWALTUNG GMBH
Application year: 1997
Main classification: G06F17
IPC codes: G06F3, G06Q10, G06Q30, G06Q50, H04M3, H04M11