Providing context facts

1. A computer-implemented method comprising:

receiving one or more lists of entities, each list (i) having an associated score, (ii) being associated with a respective context fact, and (iii) ranking a subset of the entities, the subset including two or more entities, each entity of the subset being ranked relative to each other entity in the subset of entities included in the list based on a respective value of the respective context fact for the entity;

for each of the lists of entities, generating, for each entity on the list, a data structure that references (i) the entity, (ii) the context fact associated with the list, (iii) the rank of the entity for the context fact, the rank specifying the ranking of the entity relative to each other entity in the subset of entities included in the list based on the value of the respective contact fact for the entity, and (iv) the score for the list;

receiving data identifying a particular entity and an attribute that corresponds to the value for the respective context fact for the entity;

selecting, based on the entity and the attribute, a particular data structure that references the particular entity; and

providing, for output, data indicating (i) the context fact associated with the particular data structure that references the particular entity, and (ii) the rank of the entity for the context fact associated with the particular data structure that references the particular entity.

2. The computer-implemented method of claim 1 , wherein the score of each list is based on a frequency of recent search queries including the list.

3. The computer-implemented method of claim 1 , wherein the particular data structure is selected based on the score of the list that references the particular entity.

4. The computer-implemented method of claim 1 , further comprising:

providing, for output, data indicating (i) the subset of the entities, each entity of the subset of entities being referenced by the particular data structure, and (ii) the ranking for each entity of the subset of the entities.

5. The computer-implemented method of claim 4 , further comprising:

providing a comparison between the data indicating the ranking for each entity of the subset of entities and a ranking threshold;

selecting one or more entities of the subset of the entities based on the comparison; and

providing, for output, data indicating (i) the one or more selected entities and (ii) the ranking for each entity of the selected entities.

6. The computer-implemented method of claim 1 , further comprising:

generating natural language text corresponding to the data indicating (i) the context fact associated with the particular data structure that references the particular entity, and (ii) the rank of the entity for the context fact associated with the particular data structure that references the particular entity; and

providing, for output, the natural language text.

7. The computer-implemented method of claim 6 , wherein providing, for output, the natural language text comprises providing the natural language text as audial output via one or more of text-to-speech and voice response.

8. The computer-implemented method of claim 1 , wherein receiving data identifying a particular entity comprises receiving a synonym that corresponds to the particular entity.

9. A system comprising one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:

receiving one or more lists of entities, each list (i) having an associated score, (ii) being associated with a respective context fact, and (iii) ranking a subset of the entities, the subset including two or more entities, each entity of the subset being ranked relative to each other entity in the subset of entities included in the list based on a respective value of the respective context fact for the entity;

for each of the lists of entities, generating, for each entity on the list, a data structure that references (i) the entity, (ii) the context fact associated with the list, (iii) the rank of the entity for the context fact, the rank specifying the ranking of the entity relative to each other entity in the subset of entities included in the list based on the value of the respective contact fact for the entity, and (iv) the score for the list;

receiving data identifying a particular entity and an attribute that corresponds to the value for the respective context fact for the entity;

selecting, based on the entity and the attribute, a particular data structure that references the particular entity; and

providing, for output, data indicating (i) the context fact associated with the particular data structure that references the particular entity, and (ii) the rank of the entity for the context fact associated with the particular data structure that references the particular entity.

10. The system of claim 9 , wherein the score of each list is based on a frequency of recent search queries including the list.

11. The system of claim 9 , wherein the particular data structure is selected based on the score of the list that references the particular entity.

12. The system of claim 9 , wherein the operations further comprise:

providing, for output, data indicating (i) the subset of the entities, each entity of the subset of entities being referenced by the particular data structure, and (ii) the ranking for each entity of the subset of the entities.

13. The system of claim 12 , wherein the operations further comprise:

providing a comparison between the data indicating the ranking for each entity of the subset of entities and a ranking threshold;

selecting one or more entities of the subset of the entities based on the comparison; and

providing, for output, data indicating (i) the one or more selected entities and (ii) the ranking for each entity of the selected entities.

14. The system of claim 9 , wherein the operations further comprise:

generating natural language text corresponding to the data indicating (i) the context fact associated with the particular data structure that references the particular entity, and (ii) the rank of the entity for the context fact associated with the particular data structure that references the particular entity; and

providing, for output, the natural language text.

15. The system of claim 14 , wherein providing, for output, the natural language text comprises providing the natural language text as audial output via one or more of text-to-speech and voice response.

16. The system of claim 9 , wherein receiving data identifying a particular entity comprises receiving a synonym that corresponds to the particular entity.

17. A non-transitory computer-readable storage device storing software comprising instructions executable by one or more computers which, upon such execution, cause the one or more computers to perform operations comprising:

receiving one or more lists of entities, each list (i) having an associated score, (ii) being associated with a respective context fact, and (iii) ranking a subset of the entities, the subset including two or more entities, each entity of the subset being ranked relative to each other entity in the subset of entities included in the list based on a respective value of the respective context fact for the entity;

for each of the lists of entities, generating, for each entity on the list, a data structure that references (i) the entity, (ii) the context fact associated with the list, (iii) the rank of the entity for the context fact, the rank specifying the ranking of the entity relative to each other entity in the subset of entities included in the list based on the value of the respective contact fact for the entity, and (iv) the score for the list;

receiving data identifying a particular entity and an attribute that corresponds to the value for the respective context fact for the entity;

selecting, based on the entity and the attribute, a particular data structure that references the particular entity; and

providing, for output, data indicating (i) the context fact associated with the particular data structure that references the particular entity, and (ii) the rank of the entity for the context fact associated with the particular data structure that references the particular entity.

18. The non-transitory computer-readable storage device of claim 17 , wherein the score of each list is based on a frequency of recent search queries including the list.

19. The non-transitory computer-readable storage device of claim 17 , wherein the particular data structure is selected based on the score of the list that references the particular entity.

20. The non-transitory computer-readable storage device of claim 17 , wherein the operations further comprise:

providing, for output, data indicating (i) the subset of the entities, each entity of the subset of entities being referenced by the particular data structure, and (ii) the ranking for each entity of the subset of the entities.