## 3 Materials and Methods  
### Research Design  
To empirically test the structural model presented in Figure 3, this study employed Partial Least Squares Structural Equation Modeling (PLS-SEM) using SmartPLS 4.1.0 for hypothesis testing. PLS-SEM is well-suited for estimating path models with latent variables, particularly for analyses with small sample sizes [95]. It provides reliable estimates even for complex model structures and demonstrates strong predictive capabilities, aligning with our research objective of predicting individuals' continuance usage intention toward MOCCA. Moreover, PLS-SEM allows for the simultaneous estimation of both measurement and structural models and is particularly well-suited for testing indirect effects in mediation paths [96], such as those proposed in our SOR-based framework. Our analytical approach was twofold: first, we verified the reliability and validity of the measurement model to ensure an accurate representation of constructs. Second, we conducted path analysis within the structural model to test the proposed hypotheses [97].  
This study's questionnaire consisted of two parts. The first part collected demographic information of participants, including gender, age, educational background, occupational background, usage duration, usage frequency, and usage purposes. The second part included items designed to measure each of the seven constructs in the proposed model. All these measures were drawn from previously validated research, and the measurement questions for each construct were adapted or modified from existing studies. These question items were rated on a seven-point Likert scale, ranging from strongly disagree (1) to strongly agree (7). The constructs and their corresponding measurement items are presented in Table 1.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Constructs** & **Items** & **Measurements** & **Ref.** \\ \hline \multirow{8}{*}{Intimacy} & PAI1 & I feel that MOCCA is friendly to me, like a friend. & \\  & PAI2 & I think MOCCA is sociable and enjoys interacting with me. & \\  & PAI3 & I would like to have more conversations with MOCCA. & [98] \\  & PAI4 & I feel emotionally close to MOCCA. & \\  & PAI5 & I believe that MOCCA and I share a close relationship. & \\ \hline \multirow{8}{*}{Morality} & PAM1 & MOCCA can think through whether a conversation is moral. & \\  & PAM2 & MOCCA feels obligated to engage in conversations in a moral way. & \\  & PAM3 & MOCCA has a sense for what is right and wrong. & \\  & PAM4 & MOCCA behaves according to moral rules in its conversations. & \\  & PAM5 & MOCCA would refrain from doing things that cause & \\  & PAM2 & MOCCA’s conversations are the result of its programming. & \\ \cline{1-1}  & PAD3 & MOCCA can only do what humans tell it to do. & \\ \cline{1-1}  & PAD4 & MOCCA would never engage in a conversation it was not programmed & \\ \hline \multirow{8}{*}{Information Privacy Risk} & IPR1 & The personal information collected by MOCCA may be misused. & \\ \cline{1-1}  & IPR2 & The personal information collected by MOCCA may be disclosed to & \\ \cline{1-1}  & IPR3 & The personal information collected by MOCCA may be used improperly. & [56; 99] \\ \cline{1-1}  & IPR4 & I believe it is difficult to ensure the confidentiality of personal & \\ \cline{1-1}  & IPR5 & I believe there is a risk that MOCCA may collect personal conversations & \\ \cline{1-1}  & & and share them with others. & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Constructs and items.