Methods and apparatus to determine viewing condition probabilities

1. A method, comprising:

enumerating, by executing an instruction with a processor, a list of viewing combinations for a tuning event for a number of people at a location, the viewing combinations including a viewing combination in which none of the people are viewing the tuning event;

determining, by executing an instruction with the processor, a probability for each of the viewing combinations using an independent probability of viewing for each one of the people at the location; and

determining, by executing an instruction with the processor, a probability of a viewing condition using the probabilities of a first set of the viewing combinations that have a first common characteristic, the first set of the viewing combinations being a subset of the viewing combinations and the probability of the viewing condition being independent of an order in which each one of the people is selected for calculating the probability of the viewing condition.

2. The method of claim 1 , wherein the first common characteristic is a number of viewers.

3. The method of claim 1 , wherein the first common characteristic is a first one of the people viewing the turning event.

4. The method of claim 1 , further including:

determining, by executing an instruction with the processor, the probability of the viewing condition using the probabilities of a second set of the viewing combinations that have a second common characteristic different from the first common characteristic, the second set of the viewing combinations being a second subset of the viewing combinations.

5. The method of claim 1 , wherein the viewing condition is an unconditional probability for a given number of viewers; and

the unconditional probability for the given number of viewers is determined by summing, by executing an instruction with the processor, the probability of each one of the viewing combinations having the given number of viewers.

6. The method of claim 1 , wherein the viewing condition is a normalized probability of a first one of the viewing combinations when a given number of the people are viewing the tuning event; and

the normalized probability of the first one of the viewing combinations when the given number of the people are viewing the tuning event is determined by dividing, by executing an instruction with the processor, the probability of the first one of the viewing combinations by a sum of the probability of each of the viewing combinations for the given number of the people viewing the tuning event.

7. The method of claim 1 , wherein the viewing condition is a probability for a given number of people viewing the tuning event when a first one of the people is viewing the tuning event; and

the probability for the given number of people viewing the tuning event when the first one of the people is viewing the tuning event is determined by summing, by executing an instruction with the processor, the probability of each one of the viewing combinations for the given number of people viewing the tuning event including the first one of the people viewing the tuning event, divided by a sum of the probability of each one of the viewing combinations with the first one of the people viewing the tuning event.

8. The method of claim 1 , wherein the location has more than one media device.

9. The method of claim 1 , wherein the first set of the viewing combinations has only one member.

10. The method of claim 1 , wherein the location is a panelist household.

11. The method of claim 1 , further including:

assigning, by executing an instruction with the processor, a first one of the people to the tuning event based on the probability of the viewing condition.

12. The method of claim 11 , wherein the first one of the people is assigned to the tuning event when the probability of the viewing condition exceeds a threshold probability.

13. An apparatus, comprising:

an information obtainer that obtains tuning information for a tuning event;

a combination enumerator that enumerates a list of viewing combinations for the tuning event for a number of people at a location, the viewing combinations including a viewing combination in which none of the people are viewing the tuning event;

a probability calculator that determines a probability for each of the viewing combinations using an independent probability of viewing for each one of the people at the location, the probability calculator to determine a probability of a viewing condition using the probabilities of a first set of the viewing combinations that have a first common characteristic, the first set of the viewing combinations being a subset of the viewing combinations and the probability of the viewing condition being independent of an order in which each one of the people is selected for calculating the probability of the viewing condition, at least one of the information obtainer, the combination enumerator or the probability calculator including hardware.

14. The apparatus of claim 13 , wherein the first common characteristic is a number of viewers.

15. The apparatus of claim 13 , wherein the first common characteristic is a first one of the people viewing the tuning event.

16. The apparatus of claim 13 , wherein the probability of the viewing condition is determined using the probabilities of a second set of the viewing combinations that have a second common characteristic different from the first common characteristic.

17. The apparatus of claim 13 , wherein the viewing condition is an unconditional probability for a given number of viewers; and

the unconditional probability for the given number of viewers is determined by summing the probability of each one of the viewing combinations having the given number of viewers.

18. The apparatus of claim 13 , wherein the viewing condition is a normalized probability of a first one of the viewing combinations when a given number of the people are viewing the tuning event; and

the normalized probability of the first one of the viewing combinations when the given number of the people are viewing the tuning event is determined by dividing the probability of the first one of the viewing combinations by a sum of the probability of each one of the viewing combinations for the given number of the people viewing the tuning event.

19. The apparatus of claim 13 , wherein the viewing condition is a probability for a given number of people viewing the tuning event when a first one of the people is viewing the tuning event; and

the probability for the given number of people viewing the tuning event when the first one of the people is viewing the tuning event is determined by summing the probability of each one of the viewing combinations for the given number of people viewing the tuning event including the first one of the people viewing the tuning event, divided by a sum of the probability of each one of the viewing combinations with the first one of the people viewing the tuning event.

20. The apparatus of claim 13 , wherein the location has more than one media device.

21. The apparatus of claim 13 , wherein the first set of viewing combinations has only one member.

22. The apparatus of claim 13 , wherein the location is a panelist household.

23. The apparatus of claim 13 , wherein one of the people is assigned to the tuning event based on the probability of the viewing condition.

24. The apparatus of claim 23 , wherein the first one of the people is assigned to the tuning event when the probability of the viewing condition exceeds a threshold probability.

25. A tangible computer readable medium comprising computer readable instructions which, when executed, cause a processor to at least:

enumerate a list of viewing combinations for a tuning event for a number of people at a location, the viewing combinations including a viewing combination in which none of the people are viewing the tuning event;

determine a probability for each of the viewing combinations using an independent probability of viewing for each one of the people at the location; and

determine a probability of a viewing condition using the probabilities of a first set of the viewing combinations that have a first common characteristic, the first set of the viewing combinations being a subset of the viewing combinations, the probability of the viewing condition being independent of an order in which each one of the people is selected for calculating the probability of the viewing condition.

26. The storage medium as defined in claim 25 , wherein the first common characteristic is a number of viewers.

27. The storage medium as defined in claim 25 , wherein the first common characteristic is a first one of the people viewing the tuning event.

28. The storage medium as defined in claim 25 , further including instructions which, when executed, cause a processor to at least:

determine the probability of the viewing condition using the probabilities of a second set of the viewing combinations that have a second common characteristic different from the first common characteristic.

29. The storage medium as defined in claim 25 , wherein the viewing condition is an unconditional probability for a given number of viewers; and

the unconditional probability for the given number of viewers is determined by summing the probability of each one of the viewing combinations having the given number of viewers.

30. The storage medium as defined in claim 25 , wherein the viewing condition is a normalized probability of a first one of the viewing combinations when a given number of the people are viewing the tuning event; and

the normalized probability of the first one of the viewing combinations when the given number of the people are viewing the tuning event is determined by dividing the probability of the first one of the viewing combinations by a sum of the probability of each one of the viewing combinations for the given number of the people viewing the tuning event.

31. The storage medium as defined in claim 25 , wherein the viewing condition is a probability for a given number of people viewing the tuning event when a first one of the people is viewing the tuning event; and

the probability for the given number of people viewing the tuning event when the first one of the people is viewing the tuning event is determined by summing the probability of each one of the viewing combinations for the given number of people viewing the tuning event including the first one of the people viewing the tuning event, divided by a sum of the probability of each one of the viewing combinations with the first one of the people viewing the tuning event.

32. The storage medium as defined in claim 25 , wherein the location has more than one media device.

33. The storage medium as defined in claim 25 , wherein the first set of the viewing combinations has only one member.

34. The storage medium as defined in claim 25 , wherein the location is a panelist household.

35. The storage medium as defined in claim 25 , further including instructions which, when executed, cause a processor to at least:

assign one of the people to the tuning event based on the probability of the viewing condition.