# Can Gestural Filler Reduce User-Perceived Latency in Conversation with Digital Humans?
## 4 Study 1
### Discussion  
Overall, our results indicate whether conversation and gesture types are matched or not has a strong effect on the perception of latency in conversation with digital humans. Participants were more tolerant of the delays towards digital humans who exhibited appropriate gestures. However, the appropriateness of the gesture varied by the conversation.  
In this study, we divided question-answer types of conversation into two groups: informative and casual. In the casual category, questions were related to one's own information, thoughts, or past experiences; in contrast, questions in the informative conversation type were related to objective facts, such as bus fare or a library's closing time. In other words, if the answerer were an actual human, answers for casual conversation could be obtained by thinking, and for informative conversation, answers could be acquired by searching external sources, such as the Internet. Interestingly, participants, in general, expected similar behavior from digital humans (Figure 5b, Table 2). In casual conversation, participants felt digital humans exhibiting the thinking gesture were more natural than ones with typing, i.e., searching the Internet gesture (partially supporting H1). However, the differences between the gestures in perceived naturalness were not significant in informative conversation. This might be related to how participants considered digital humans, i.e., whether they thought of digital humans as social beings or mere technology. Participant P1's comment, _\"I thought that the digital human has all of the information, so he pretends to  
Figure 5: The results of (**a**) user-perceived latency, (**b**) behavioral naturalness, and (**c**) competence. (*: \(p<0.05\), **: \(p<0.01\))  
think\"_, is in line with this speculation. Similar to P1, some participants might think that the digital human knows everything, thus retrieving the information internally might seem better. Therefore, for them, the digital being using the Internet, i.e., external sources, to find information might seem awkward.  
Regarding user-perceived latency, the mismatch between conversation and gesture might have triggered the recognition of the delays and/or reassessment of digital humans (Figure 5a, Table 2). As sensorimotor incongrurency leads to breaks in presence in immersive virtual environments, inappropriate gestures could have led to breaks in social presence with digital humans, therefore reducing their tolerance of delays. It could have made participants focus--otherwise distracted--on the delay moments. While we are oblivious to the reasons yet, our results strongly indicate that participants felt less delay when digital humans exhibited appropriate gestures, i.e., matched with the context.  
In the competence of the digital human, regardless of the gestural filler, the informative conversation type had a higher score than the casual conversation type (Figure 5c, Table 2). The reason seems to be that the informative conversation type is based on objective facts, contrary to the casual conversation type.