| In this thesis, we studied persuasion in online communication and how to automate persuasive behavior in an autonomous chat agent. We implemented known persuasive strategies into the agent, which are based upon the strength and evaluation of the beliefs expressed by participants in conversation, to induce belief change. The foundation of our persuasive strategies comes from the summative model of attitude, where belief change leads to attitude change, and, ultimately, behavior change. Upon placing an agent in the midst of conversations, it is able to discern beliefs that are expressed by the participants in the group, and use them to ascertain participant's opinions on topics of discussion. Using this information and drawing upon theories of influence and persuasion from social psychology, cognitive science and communication, the agent aligns participants towards or against a particular issue.;We organized the work in three phases. First, we conducted a belief elicitation study to obtain salient beliefs on a variety of social issues and used these salient beliefs to create survey instruments. Next, we programmed behaviors and strategies in the agent that were aimed at persuading individuals through online conversation as well as counteracting persuasion by the participants. The behaviors programmed in the agents are triggered, in part, by a variety of linguistic cues emerging from the conversation, such as dialogue acts, topic, polarity and communication acts. The annotated context of conversation is used to inform the agent's models by updating the underlying beliefs of participants in real time. Third, we ran controlled experiments with human participants to validate the chat agent in a variety of settings, including Wizard-of-Oz and autonomous agent conditions to determine the efficacy of its programmed strategies. In the validation experiments, we used pre-discussion and post-discussion surveys to determine changes in participants' attitudes prior to and after a discussion. We showed that the agent achieved statistically significant changes in the participant's attitudes, thus demonstrating its effectiveness in being persuasive. Through our work, we have shown that specific persuasion strategies can be automated as well as counteracted using sophisticated communication models built upon sociolinguistic and psychological theories of social influence. |
