# Vehicle Politeness in Driving Situations
## 2 Related Works
### Politeness for Cooperation  
People are polite to each other in order to cooperate and form relationships. Politeness stems from an innate human ability to give consideration to other people. Humans, being social animals, have psychological mechanisms to form relationships and cooperate with one another. One of the premises of social relations is that people seek benefits through interactions. People form relationships to achieve greater goals more efficiently. For a cooperation to occur, all members of the cooperation should value practical benefits of the cooperation highly. If the benefits are one-sided, the other side may respond passively to the cooperation or even reject the relationship. As people are sensitive to the utility of cooperation, they naturally project that others also seek benefits from the relationship. Thus, people have a sophisticated sense of recognizing the benefits to both themselves and their cooperation partners. Politeness is the mutual respect people have for each other to ensures cooperation. Politeness theory [16] explains this reciprocal consideration in terms of face-saving intentions, which reflects the respect for each other's ideal social self. The theory assumes that people have an ideal social self, the face, which they wish to be respected by others. Every individual has a desire to maintain the face. Since people have natural social capabilities, people can easily make sense of whether they are treated well by their interaction partners. Even when the partners are machines, people are still sensitive about the machines' politeness. If machines are polite to users by respecting their face, the users can expect more benefits from the relationships. Politeness of computers has been widely studied and has been found to enhance the interaction experience [17; 18; 19; 20; 21; 22; 23; 24]. In general, a machine following the politeness rule tends to be perceived as a better interaction partner. To be specific, [PERSON] suggested a way of improving interaction by maximizing user's choice with the openness of computer request [20]. Forcing users to only accept error messages would be impolite, so it is not recommended. In addition, the etiquette of computers can increase their credibility, as people have more trust in a person with a decent etiquette. Another study argued that people had more trust in a system that did not interfere with human operations [19]. Therefore, vehicle politeness can positively influence drivers' user experience (UX) and promote their intentions to cooperate with the vehicle. Based on the above discussion, we suggest the following hypothesis. **Hypothesis 1**: _Drivers using a polite driving assistant will show more positive evaluations of the system than drivers using a plain assistant._  
The theory also suggests that people choose speech strategies by considering both a speaker's wants and a listener's burden. The magnitude of imposition posed by requests is a huge determinant of choosing a strategy. As the burden of requests increased, a speaker would choose a strategy with a higher degree of politeness. They can simply express appreciation, emphasize relationships or offer future rewards. They also can try to be indirect or apologetic for making the requests. Following that, it is a logical assumption that there will be an increased requirement of vehicle politeness as situations demand a heavier burden of requests. With this rationale, the following hypothesis is proposed. **Hypothesis 2**: _Effects of vehicle politeness will be higher in task failure situations than normal working situations._  
The voice interface is the platform for conveying vehicle politeness. In general, it is recommended that speech interfaces give short instructions to ensure efficient interaction [25]. Given the unfriendly nature of driving instructions, however, the pursuit of mere efficiency can lead drivers to feel antipathy towards dominant instructions.