# Speech Act Theory as an Evaluation Tool for Human-Agent Communication
## 7 Discussion
Similarly, in collaborations involving agents, researchers have found that understanding intentions is fundamental in collaborative tasks ([PERSON] and [PERSON], 2018). The third research question inquired about how to evaluate the agent's perlocutionary acts. The analysis of tracking data in the log files showed that the participants' acceptance of the agent's requests increased from 64.41% to 70.69% in the last cycle. This increase could be explained by the increasing exposure of participants to the agent's verbal communication, which led to the development of a shared understanding between the human participant and the agent, or what is called a shared mental model. A number of studies have argued that the exposure to communication positively affects the degree of coordinated performance attained by teammates. Communication was found to play an important role in teamwork achievements ([PERSON] and [PERSON], 2018). According to some research, communication in computer-based environments does not differ from face-to-face communication in terms of the capabilities for social information exchange ([PERSON] and [PERSON], 2018). The result of our study is in line with previous studies that showed the positive impact of communication on tuning team performance ([PERSON] and [PERSON], 2018). In ([PERSON] and [PERSON], 2018), communication was found to uncover any uncertainty team members may have, increasing team effectiveness and improving team performance. The fourth research question asked whether human understanding of the agent's intention is associated with human perceptions of the consequences of the agent's utterance. The result revealed that humans' perceptions of the agent's illocutionary acts and their perceptions of the agent's perlocutionary acts are significantly correlated. Moreover, the result showed that human understanding of the agent's intention through speech is likely to be a predictor of human perceptions of the consequences of the speech. The literature reveals conflicting opinions regarding whether illocutionary acts are sufficient to develop the interlocutor's understanding of the consequences of speech. Some researchers believe that perception of the collaborative environment is hard to establish by exchanging messages because message exchange could fail anytime ([PERSON] and [PERSON], 2018). Some other work goes to the other extreme and assumes the understanding of uttered messages to be a key factor in forming an understanding of other interlocutors and incidents in a collaborative situation ([PERSON] and [PERSON], 2018). Although our experiments did not investigate other possible factors that might contribute to the participants' understanding of the agent's perlocutionary acts, the results showed the importance of participants' understanding of the agent'sintention expressed in locutionary acts to support participant expectations of the consequences of verbal communication in a collaboration situation. The results stemming from the last research question demonstrated that there is a significant correlation between human perception of the agent's intention in verbal communication and the consequences of this communication, as well as the human perception of the collaboration performance. In addition, the results revealed that human perceptions of the agent's intention and the consequences of speech are likely to be a predictor of human perceptions of the collaboration outcome. The answer to the second part of the fourth question revealed that participants' perceptions of the agent's illocutionary acts contribute more to their perception of collaboration performance. To the best of our knowledge, there is no research in the literature that has studied an agent's illocutionary and perlocutionary acts and their impact on a task-oriented collaboration with humans. Nevertheless, there are a number of studies that argue the importance of communication as a facilitator in successful teamwork [50] and in improving coordinated performance [51].