Learning from interactions for a spoken dialog system

1. A method comprising:

obtaining, during an unsupervised classification phase of a spoken dialog system, a semantic classifier input and a corresponding label attributed to the semantic classifier input;

determining, via a processor, whether the corresponding label is correct based on logged interaction data, to yield a correctness result, wherein the logged interaction data comprises:

data describing user speech;

a non-speech user action indicating one of a negative training example and a positive training example; and

an input/output pair having an input and an output, the input comprising a speech recognition result in a lattice form and the output comprising one of an outcome of a call, a confirmation by a user, and a call hang-up, the output being a result of the input;

generating an entry for an adaptation corpus based on the correctness result; and

adapting operation of a semantic classifier based on the adaptation corpus.

2. The method of claim 1 , wherein determining whether the corresponding label is correct indicates whether the label attributed by the semantic classifier is one of a correct label and an incorrect label.

3. The method of claim 1 , wherein determining whether the corresponding label is correct further comprises:

calculating a confidence level indicative of an estimated probability that the label attributed by the semantic classifier is correct; and

determining that the label attributed by the semantic classifier is correct when the calculated confidence level is greater than a predetermined threshold.

4. The method of claim 1 , wherein when the corresponding label is not correct, the method further comprises:

determining a correct label based on logged interaction data;

calculating a confidence level indicative of an estimated probability that the correct label is correct; and

recording the semantic classifier input, the correct label and the confidence level in a respective entry of the adaptation corpus.

5. The method of claim 1 , wherein adapting operation of the semantic classifier based on the adaptation corpus further comprises:

using a boosting method to adapt the semantic classifier.

6. A system comprising:

a processor; and

a computer-readable storage medium having instructions stored which, when executed by the processor, cause the processor to perform operations comprising:

obtaining, during an unsupervised classification phase of a spoken dialog system, a semantic classifier input and a corresponding label attributed to the semantic classifier input;

determining, via a processor, whether the corresponding label is correct based on logged interaction data, to yield a correctness result, wherein the logged interaction data comprises:

data describing user speech;

a non-speech user action indicating one of a negative training example and a positive training example; and

an input/output pair having an input and an output, the input comprising a speech recognition result in a lattice form and the output comprising one of an outcome of a call, a confirmation by a user, and a call hang-up, the output being a result of the input;

generating an entry for an adaptation corpus based on the correctness result; and

adapting operation of a semantic classifier based on the adaptation corpus.

7. The system of claim 6 , further comprising:

a dialog manager associated with the spoken dialog system configured to control the processor to receive the corresponding label and to determine one of a plurality of actions to perform based on the corresponding label.

8. The system of claim 7 , wherein:

the dialog manager is further configured to control the processor to record interactions to the logged interaction data.

9. The spoken dialog system of claim 6 , wherein determining whether the corresponding label is correct further comprises:

calculating a confidence level indicative of an estimated probability that the corresponding label is correct; and

determining that the corresponding label is correct when the calculated confidence level is greater than a predetermined threshold.

10. The system of claim 6 , the computer-readable storage medium having additional instruction stored which result in the operations further comprising:

when the corresponding label is not correct:

determining a correct label based on the logged interaction data; and

calculating a confidence level indicative of an estimated probability that the correct label is correct; and

recording the semantic classifier input, the correct label and the confidence level in a respective entry of the adaptation corpus.

11. The system of claim 6 , wherein the semantic classifier is arranged to adapt its operation based on the adaptation corpus by using a boosting method.

12. A computer-readable storage device having instructions stored which, when executed by a computing device, cause the processor to perform operations comprising:

obtaining, during an unsupervised classification phase of a spoken dialog system, a semantic classifier input and a corresponding label attributed to the input by a semantic classifier;

determining whether the corresponding label is correct based on logged interaction data, to yield a correctness result, wherein the logged interaction data comprises:

data describing user speech;

a non-speech user action indicating one of a negative training example and a positive training example; and

an input/output pair having an input and an output, the input comprising a speech recognition result in a lattice form and the output comprising one of an outcome of a call, a confirmation by a user, and a call hang-up, the output being a result of the input;

generating an entry for an adaptation corpus based on the correctness result result; and

adapting operation of a semantic classifier based on the adaptation corpus.

13. The computer-readable storage device of claim 12 , the computer-readable storage device having additional instructions stored which result in the operations further comprising recording interactions of a component of the spoken dialog system to the logged interaction data.

14. The computer-readable storage device of claim 12 , wherein determining whether the corresponding label is correct based on logged interaction data further comprises:

calculating a confidence level indicative of an estimated probability that the corresponding label attributed by the semantic classifier is correct; and

determining that the corresponding label attributed by the semantic classifier is correct when the calculated confidence level is greater than a predetermined threshold.

15. The computer-readable storage device of claim 12 , wherein determining whether the corresponding label is correct based on logged interaction data, further comprises:

determining when the corresponding label is not correct;

determining a correct label based on the logged interaction data;

calculating a confidence level indicative of an estimated probability that the determined correct label is correct; and

recording the semantic classifier input, the correct label and the confidence level in a respective entry of the adaptation corpus.

16. The computer-readable storage device of claim 12 , wherein determining whether the corresponding label is correct based on logged interaction data further comprises:

recording a confidence level to the adaptation corpus only when the corresponding label is determined to be incorrect.

17. The computer-readable storage device of claim 12 , wherein adapting operation of the semantic classifier based on the adaptation corpus further comprises:

using a boosting method to adapt the semantic classifier.