Method and system for facilitating a guided dialog between a user and a conversational agent

Patent metadata

Field	Value
Publication number	US-10672397-B2
Application number	US-201916522864-A
Country	US
Kind code	B2
Filing date	Jul 26, 2019
Priority date	Sep 9, 2016
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

The present teaching relates to facilitating a guided dialog with a user. In one example, an input utterance is obtained from the user. One or more task sets are estimated based on the input utterance. Each of the one or more task sets includes a plurality of tasks estimated to be requested by the user via the input utterance and is associated with a confidence score computed based on statistics with respect to the plurality of tasks in the task set. At least one of the one or more task sets is selected based on their respective confidence scores. A response is generated based on the tasks in the selected at least one task set. The response is provided to the user.

First claim

We claim:

1. A method, implemented on a machine having at least one processor, storage, and a communication platform connected to a network for generating a task lineage associated with a dialog of a user, the method comprising:
obtaining an input utterance from the user;
determining one or more task sets estimated based on the input utterance, wherein each of the one or more task sets includes a plurality of tasks estimated to be requested by the user;
computing a confidence score associated with each of the one or more tasks, wherein the confidence score is inversely proportional to a time interval between the input utterance and a last utterance by the user;
selecting at least one of the one or more task sets based on their respective confidence scores;
extracting one or more task lineages of the user from a task state database;
generating one or more new task lineages based on the selected at least one task set;
determining coherent features between the extracted one or more task lineages and the one or more new task lineages;
extending each of the extracted one or more task lineages of the user based on a belief score estimated for each new task lineage; and
providing the one or more task lineages to the user in response to the input utterance.

2. The method of claim 1 , wherein the belief score is estimated for each new task lineage based on the coherent features and the confidence scores of the tasks in the selected at least one task set.

3. The method of claim 2 , wherein determining one or more task sets further comprises:
reassigning at least one of the plurality of dialog act items to a different task frame candidate to generate a second set of task frame candidates;
determining a second task set that includes a plurality of tasks corresponding to the second set of task frame candidates;
determining a task slot value for each of the plurality of dialog act items based on the reassignment with respect to the second set of task frame candidates; and
calculating a second confidence score associated with the second task set.

4. The method of claim 1 , wherein the confidence score is computed based on statistics with respect to the plurality of tasks in the task set.

5. The method of claim 1 , further comprising:
determining relevant context information based on the extracted one or more task lineages and the selected at least one task set;
determining a context window representing a time period within which the relevant context information can be fetched;
retrieving the relevant context information from a database based on the context window; and
updating at least one task slot value of the sequence of tasks in the extracted one or more task lineages based on the retrieved relevant context information.

6. The method of claim 1 , wherein determining one or more task sets comprises:
determining a plurality of dialog act items based on a semantic analysis of the input utterance;
assigning each of the plurality of dialog act items to a task frame candidate to generate a first set of task frame candidates, wherein at least one of the plurality of dialog act items is shared by two or more task frame candidates;
determining a first task set that includes a plurality of tasks corresponding to the first set of task frame candidates;
determining a task slot value for each of the plurality of dialog act items based on the assignment with respect to the first set of task frame candidates; and
calculating a first confidence score associated with the first task set.

7. The method of claim 6 , wherein the first confidence score is calculated based on one of the following statistics:
the number of task frames in the first set of task frame candidates;
the number of dialog act items assigned to each task frame candidate;
the average number of dialog act items per active task frames in the first set of task frame candidates;
the entropy of dialog act item distribution across the active task frames; and
the number of active task frames with only one dialog act item.

8. A non-transitory machine-readable medium having information recorded thereon for generating a task lineage associated with a dialog of a user, wherein the information, when read by the machine, causes the machine to perform the following:
obtaining an input utterance from the user;
determining one or more task sets estimated based on the input utterance, wherein each of the one or more task sets includes a plurality of tasks estimated to be requested by the user;
computing a confidence score associated with each of the one or more tasks, wherein the confidence score is inversely proportional to a time interval between the input utterance and a last utterance by the user;
selecting at least one of the one or more task sets based on their respective confidence scores;
extracting one or more task lineages of the user from a task state database;
generating one or more new task lineages based on the selected at least one task set;
determining coherent features between the extracted one or more task lineages and the one or more new task lineages;
extending each of the extracted one or more task lineages of the user based on a belief score estimated for each new task lineage; and
providing the one or more task lineages to the user in response to the input utterance.

9. The medium of claim 8 , wherein the belief score is estimated for each new task lineage based on the coherent features and the confidence scores of the tasks in the selected at least one task set.

10. The medium of claim 9 , wherein determining one or more task sets further comprises:
reassigning at least one of the plurality of dialog act items to a different task frame candidate to generate a second set of task frame candidates;
determining a second task set that includes a plurality of tasks corresponding to the second set of task frame candidates;
determining a task slot value for each of the plurality of dialog act items based on the reassignment with respect to the second set of task frame candidates; and
calculating a second confidence score associated with the second task set.

11. The medium of claim 8 , wherein the confidence score is computed based on statistics with respect to the plurality of tasks in the task set.

12. The medium of claim 8 , further comprising:
determining relevant context information based on the extracted one or more task lineages and the selected at least one task set;
determining a context window representing a time period within which the relevant context information can be fetched;
retrieving the relevant context information from a database based on the context window; and
updating at least one task slot value of the sequence of tasks in the extracted one or more task lineages based on the retrieved relevant context information.

13. The medium of claim 8 , wherein determining one or more task sets comprises:
determining a plurality of dialog act items based on a semantic analysis of the input utterance;
assigning each of the plurality of dialog act items to a task frame candidate to generate a first set of task frame candidates, wherein at least one of the plurality of dialog act items is shared by two or more task frame candidates;
determining a first task set that includes a plurality of tasks corresponding to the first set of task frame candidates;
determining a task slot value for each of the plurality of dialog act items based on the assignment with respect to the first set of task frame candidates; and
calculating a first confidence score associated with the first task set.

14. The medium of claim 13 , wherein

Assignees

• Oath Inc

Inventors

• Lee Sungjin
• Stent Amanda

Classifications

• G10L2015/223

  Execution procedure of a spoken command · CPC title

• G06F16/24522

  Translation of natural language queries to structured queries · CPC title

• G10L15/22 Primary

  Procedures used during a speech recognition process, e.g. man-machine dialogue · CPC title

• G10L15/1822

  Parsing for meaning understanding · CPC title

• G06F16/3329

  Natural language query formulation · CPC title