Providing responses in an event-related session

1. A method for providing responses in an event-related conversational session, the event being associated with a predefined domain, the conversational session comprising an electronic conversational agent and at least one participant, the method comprising:

detecting at least one message from the at least one participant, the at least one message including a stance relating to an entity participating in the event;

retrieving, from an index set being based on the domain, a set of candidate responses according to the at least one message;

optimizing the set of candidate responses through filtering the set of candidate responses according to predetermined criteria, wherein filtering includes:

filtering out responses from the set of candidate responses that are inconsistent with a predetermined stance of the electronic conversational agent, the predetermined stance being one of a preference or a degree of support for entities participating in the event, wherein one of keyword matching or pattern matching is used to identify ones of the set of candidate responses that are inconsistent with the predetermined stance;

retrieving candidate responses having stances that align with the stance relating to the entity in the set of candidate responses and are consistent with the predetermined stance, the candidate responses having the stances aligning with the stance relating to the entity; and

selecting a conversational response to the at least one message from the filtered set of candidate responses; and

providing the selected conversational response by the electronic conversational agent in the conversational session such that the electronic conversational agent appears as part of the conversational session.

2. The method of claim 1 , wherein the filtering comprises:

determining an opinion to a fact in the event by each of the set of candidate responses; and

retaining candidate responses having a same opinion as a previous opinion to the fact in the set of candidate responses.

3. The method of claim 1 , wherein the filtering comprises:

determining an opinion to a fact in the event by the at least one message; and

retaining candidate responses having the opinion to the fact in the set of candidate responses.

4. The method of claim 1 , wherein the filtering comprises:

obtaining background information related to an entity in the event;

determining a time point of the background information; and

retaining candidate responses being related to the entity and having time labels later than a time point in the set of candidate responses.

5. The method of claim 1 , wherein the filtering comprises:

filtering, from the set of candidate responses, at least one of: candidate response containing advertisement; candidate response containing risky expression; context-dependent candidate response; and candidate response having been provided in the session previously.

6. The method of claim 1 , further comprising:

filtering, from the at least one message, at least one of: message containing advertisement; message containing risky expression; and pure chat message unrelated to the electronic conversational agent.

7. The method of claim 1 , wherein the retrieving comprises:

identifying an entity contained in the at least one message; and

retrieving, from the index set, the set of candidate responses containing the entity or an extension of the entity.

8. The method of claim 1 , wherein the index set comprises at least one of:

an index set established according to a corpus in the domain; and

an index set established according to corpus related to the event in the domain.

9. The method of claim 1 , wherein the selecting comprises:

ranking the filtered set of candidate responses; and

selecting a top-ranked candidate response as the response to the at least one message.

10. The method of claim 1 , further comprising:

obtaining real-time information related to the event;

generating real-time event content according to the real-time information; and

providing the real-time event content in the session.

11. The method of claim 10 , wherein the real-time information is obtained from at least one of:

an event database updated in real time; and

real-time information provided in the session by one participant in the at least one participant.

12. The method of claim 1 , wherein the at least one participant comprises at least another electronic conversational agent.

13. An apparatus for providing responses in an event-related conversational session, the event being associated with a predefined domain, the conversational session comprising an electronic conversational agent and at least one participant, the apparatus comprising:

a message detecting module, for detecting at least one message from the at least one participant, the at least one message including a stance relating to an entity participating in the event;

a retrieving module, for retrieving, from an index set being based on the domain, a set of candidate responses according to the at least one message;

a filtering module, for optimizing the set of candidate responses through filtering the set of candidate responses according to predetermined criteria, wherein filtering includes:

filtering out responses from the set of candidate responses that are inconsistent with a predetermined stance of the electronic conversational agent, the predetermined stance being one of a preference or a degree of support for entities participating in the event, wherein one of keyword matching or pattern matching is used to identify ones of the set of candidate responses that are inconsistent with the predetermined stance;

retrieving candidate responses having stances that align with the stance relating to the entity in the set of candidate responses and are consistent with the predetermined stance, the candidate responses having the stances aligning with the stance relating to the entity; and

a selecting module, for selecting a conversational response to the at least one message from the filtered set of candidate responses; and

a response providing module, for providing the selected conversational response by the electronic conversational agent in the conversational session such that the electronic conversational agent appears as part of the conversational session.

14. An apparatus for providing responses in an event-related conversational session, the event being associated with a predefined domain, the conversational session comprising an electronic conversational agent and at least one participant, the apparatus comprising:

one or more processors; and

a memory storing computer-executable instructions that, when executed, cause the one or more processors to:

detect at least one message from the at least one participant, the at least one message including a stance relating to an entity participating in the event;

retrieve, from an index set being based on the domain, a set of candidate responses according to the at least one message;

optimize the set of candidate responses through filtering the set of candidate responses according to predetermined criteria, wherein filtering includes:

filtering out responses from the set of candidate responses that are inconsistent with a predetermined stance of the electronic conversational agent, the predetermined stance being one of a preference or a degree of support for entities participating in the event, wherein one of keyword matching or pattern matching is used to identify ones of the set of candidate responses that are inconsistent with the predetermined stance;

retrieving candidate responses having stances that align with the stance relating to the entity in the set of candidate responses and are consistent with the predetermined stance, the candidate responses having the stances aligning with the stance relating to the entity; and

select a conversational response to the at least one message from the filtered set of candidate responses; and

provide the selected conversational response by the electronic conversational agent in the conversational session such that the electronic conversational agent appears as part of the conversational session.