# How Do Humans Recognize the Motion Arousal of Non-Humanoid Robots?
## 4 Experiment One
### Experimental Scale  
The scale used in this study is the Chinese version of the PAD (Pleasure-Arousal-Dominance) Emotional Scale revised by the Institute of Psychology, Chinese Academy of Sciences, based on the Chinese context [46]. The PAD scale has extensive applications in fields such as psychology, market research, and user experience design, and it can provide strong support for understanding the underlying cognitive patterns of human emotions towards Non-Humanoid Robots (NHR) in this study. Here, the focus is primarily on the degree of emotional activation and the intensity of emotions (i.e., arousal). Using the PAD scale can reveal the consistency and differences between the arousal levels of different emotional states, which helps in comparing emotional responses across various situations. At the same time, since this study employs a PAD scale revised for the Chinese context, it takes into account the characteristics of emotional expression and experience within the Chinese cultural background, enhancing the scale's applicability and accuracy. This scale converts subjective emotional experiences into quantifiable data through standardized scoring methods, facilitating statistical analysis.  
This scale has shown good reliability and construct validity. The simplified Chinese version of the PAD scale uses a 9-point semantic differential scale, with ratings ranging from \(-4\) to \(4\). The scale uses 4 sets of descriptive words for the three emotional dimensions, Pleasure (P), Arousal (A), and Dominance (D), totaling 12 sets of descriptive words. Each set of descriptive words consists of a pair of opposite adjectives for the dimension it represents, while being basically the same for other dimensions. A higher absolute rating, such as choosing 4 or \(-4\), indicates that the subject's chosen emotion is closer to the adjective at that end. The closer the score is to the middle, the lower the degree of similarity between the subject's emotional experience and the adjective. The middle score is 0, which represents that the adjectives at both ends of the group equally or weakly describe the subject's emotion. This study mainly focuses on the expression patterns of emotions through actions. Therefore, only the sets of emotional words related to the arousal dimension of the PAD scale are used, totaling 4 sets. The descriptive words for the dimensions are interspersed and arranged with reverse choices for specific question numbers. The specific dimension descriptive word groups are shown in Table 1:  
Among them, Q1, Q2, Q3, and Q4 are the vocabulary for the arousal dimension. Additionally, Q2 and Q4 are positive options, while Q1 and Q3 are reverse options. The final arousal score is obtained by calculating the mean. See Table 2 for details.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Question Number** & **Descriptive Words** \\ \hline Q1 & Wide awake—Sleepy \\ Q2 & Calm—Excited \\ Q3 & Stimulated—Relaxed \\ Q4 & Sluggish—Frenzied \\ \hline \hline \end{tabular}
\end{table}
Table 1: Dimension description phrases for arousal.  
In the scoring calculation formula, positive options are added together and reverse options are subtracted. After summing up, the result is divided by four. The mean calculation result serves as the final arousal score.