MSR develop an agent to answer questions posted on twitter. The agent uses crowdsourcing – very much a HAC!
http://research.microsoft.com/en-us/um/people/merrie/papers/crowdsourced_qna_icwsm2013.pdf
Dr. Sarvapali D. Ramchurn
Lecturer (Roberts Fellow),
Agents, Interaction, and Complexity Group,
School of Electronics and Computer Science,
University of Southampton, SO17 1BJ
t: +44 (0) 2380599309