Probabilistic methods and apparatus to determine the state of a media device
View Patent ↗Probabilistic methods and apparatus to determine the state of a media device are described. An example method includes generating, based on a first output signal from a first sensor, a first parameter value representative of a first property of a media device; generating, based on a second output signal from a second sensor, a second parameter value representative of a second property of the media device; calculating a first state probability that the media device is presenting media provided by a first source based on a first conditional probability associated with the first parameter value and a second conditional probability associated with the second parameter value; calculating a second state probability that the media device is presenting media provided by a second source different than the first source based on a third conditional probability associated with the first parameter value and a fourth conditional probability associated with the second parameter value; and generating a state identifier by comparing the first state probability and the second state probability.
1. A method, comprising:
generating, based on a first output signal from a first sensor, a first parameter value representative of a first property of a media device;
generating, based on a second output signal from a second sensor, a second parameter value representative of a second property of the media device;
calculating a first state probability that the media device is presenting media provided by a first source based on a first conditional probability associated with the first parameter value and a second conditional probability associated with the second parameter value;
calculating a second state probability that the media device is presenting media provided by a second source different than the first source based on a third conditional probability associated with the first parameter value and a fourth conditional probability associated with the second parameter value; and
generating a state identifier by comparing the first state probability and the second state probability.
2. A method as defined in claim 1 , wherein generating the state identifier comprising selecting the greater of the first state probability or the second state probability.
3. A method as defined in claim 1 , wherein the first sensor is an audio sensor and the second sensor is a light sensor.
4. A method as defined in claim 1 , wherein the first conditional probability associated with the first parameter value is calculated during a training session occurring prior to generation of the first output signal.
5. A method as defined in claim 4 , wherein the training session includes recording a first set of first parameter values and calculating a probability distribution of the first parameter values in the first set.
6. A method as defined in claim 1 , wherein the first source comprises a set-top box and the second source comprises a gaming system.
7. A method as defined in claim 1 , further comprising sending the state identifier to a metering entity.
8. An apparatus, comprising:
a parameter generator to:
generate, based on a first output signal from a first sensor, a first parameter value representative of a first property of a media device; and
generate, based on a second output signal from a second sensor, a second parameter value representative of a second property of the media device; and
a classifier to:
calculate a first state probability that the media device is presenting media provided by a first source based on a first conditional probability associated with the first parameter value and a second conditional probability associated with the second parameter value;
calculate a second state probability that the media device is presenting media provided by a second source different than the first source based on a third conditional probability associated with the first parameter value and a fourth conditional probability associated with the second parameter value; and
generate a state identifier by comparing the first state probability and the second state probability.
9. An apparatus as defined in claim 8 , wherein the classifier is to generate the state identifier by selecting the greater of the first state probability or the second state probability.
10. An apparatus as defined in claim 8 , wherein the first sensor is an audio sensor and the second sensor is a light sensor.
11. An apparatus as defined in claim 8 , wherein the first conditional probability associated with the first parameter value is calculated during a training session occurring prior to generation of the first output signal.
12. An apparatus as defined in claim 11 , wherein the training session includes recording a first set of first parameter values and calculating a probability distribution of the first parameter values in the first set.
13. An apparatus as defined in claim 8 , wherein the first source comprises a set-top box and the second source comprises a gaming system.
14. An apparatus as defined in claim 8 , further comprising a communicator to send the state identifier to a metering entity.
15. A machine readable storage device or storage disc comprising instructions that, when executed, cause a machine to at least:
generate, based on a first output signal from a first sensor, a first parameter value representative of a first property of a media device;
generate, based on a second output signal from a second sensor, a second parameter value representative of a second property of the media device;
calculate a first state probability that the media device is presenting media provided by a first source based on a first conditional probability associated with the first parameter value and a second conditional probability associated with the second parameter value;
calculate a second state probability that the media device is presenting media provided by a second source different than the first source based on a third conditional probability associated with the first parameter value and a fourth conditional probability associated with the second parameter value; and
generate a state identifier by comparing the first state probability and the second state probability.
16. A machine readable storage device or storage disc as defined in claim 15 , wherein the instructions, when executed, cause the machine to generate the state identifier by selecting the greater of the first state probability or the second state probability.
17. A machine readable storage device or storage disc as defined in claim 15 , wherein the first sensor is an audio sensor and the second sensor is a light sensor.
18. A machine readable storage device or storage disc as defined in claim 15 , wherein the first conditional probability associated with the first parameter value is calculated during a training session occurring prior to generation of the first output signal.
19. A machine readable storage device or storage disc as defined in claim 18 , wherein the training session includes recording a first set of first parameter values and calculating a probability distribution of the first parameter values in the first set.
20. A machine readable storage device or storage disc as defined in claim 15 , wherein the first source comprises a set-top box and the second source comprises a gaming system.