# Social Responses to Virtual Humans: The Effect of Human-Like Characteristics
## 2 Experiment #1: Social Facilitation
### Results  
We averaged all 13 items in the interview questionnaire to a single score for each participant to capture each participant's overall valence toward the presenter. Consistent with the interview questionnaire, higher scores indicated more positive responses toward the presenter.  
A two-way between subjects ANOVA (presenter and evaluation factor) was conducted and was followed by a post hoc Dunnett's test. Analysis was conducted on the overall valence toward the presenter (i.e., the average of all 13 items). The results (summarized in Figure 6) show that combined across presenter types, consistent with the politeness prediction, participants gave more positive responses when the presenter asked about its own performance (direct evaluation) as compared to when participants answered on paper-and-pencil (indirect evaluation). This observation was supported by a main effect of Evaluation (direct, evaluation), \(F(1,79)=10.27\), \(MSE=12.74\), \(p<0.01\). There was also a main effect of Presenter (virtual human with facial appearance only, virtual human with voice only, virtual human with voice synced facial appearance, human), \(F(3,237)=11.94\), \(MSE=14.81\), \(p<0.001\), but no Evaluation by Presenter interaction, \(F<1\).  
Post Hoc Analyses  
_Direct versus indirect:_ The main effects of Presenter and Evaluation suggest that each presenter type should be further analyzed to see whether participants applied the politeness norm to all presenter types. We conducted a post hoc Dunnett's test to compare each direct condition to the indirect condition separately for each presenter type. For each presenter type, the politeness norm was demonstrated; face only: \(t(72)=2.46\), \(p<0.05\), \(d=0.57\); voice only: \(t(72)=2.22\), \(p<0.05\), \(d=0.52\); voice synced face: \(t(72)=2.16\), \(p<0.05\), \(d=0.54\); human: \(t(72)=2.72\), \(p<0.01\), \(d=0.73\).  
_Virtual human versus human:_ Of interest was whether the social response to the virtual human was similar to that of the social response to the human. The valence toward the voice synced face condition did not differ significantly from the valence toward the human presenter condition for both direct and indirect conditions, \(t<1\). However, this valence toward the voice synced face voice was significantly higher than the valence toward the voice only condition for both direct and indirect conditions, \(t(72)=2.6\), \(p<0.05\). There was no significant difference between the voice-only condition and the face only condition for both direct and indirect conditions, \(t<1\).  
As with the previous experiment, we conducted a post hoc power analysis with the program G*Power with power set at 0.8 and \(\alpha=0.05\), \(d=0.5\), two-tailed. The results suggest an n of approximately 640 would be needed to achieve appropriate statistical power; once again the limitation of these findings will be discussed.  
Results from the politeness experiment indicate that, consistent with the politeness norm, participants who evaluated their presenter directly reported the presenter's performance more favorably than participants who evaluated their presenter indirectly. This was observed not only with the human presenter but with virtual human presenters in all four conditions. In addition, consistent with the social facilitation experiment, the valence toward the voice synced facial appearance was not significantly different from the valence toward the human presenter condition. In other words, when voice is combined with face (i.e., voice synced face) an additive effect seems to occur where the social responses to virtual humans with such features are indistinguishable from the social responses to humans.  
Figure 6: Mean valence toward the presenter for each evaluation type. (direct, indirect) for each presenter type (face only, voice only, voice synced face, human) (\(n=80\)).