## 1 Introduction
This theory is an extension of the theory of reasoned action (TRA) by [PERSON] and [PERSON] in 1975 and 1980 [19]. It states that the main factor in the TPB is the individual's intention to perform a certain behavior. Moreover, the intention is defined as motivational factors that influence behavior--how willing a person is and how much effort they intend to exert to fulfill the behavior. Multiple studies have supported and extended the TPB, including the study of [PERSON] and [PERSON] [20] Where it was found that due to the antecedents of the TPB, managers' intention to undertake crisis planning was heightened. To fully plan for a crisis, managers opt to go to workshops to learn about crisis planning and even avail consultation meetingswith professionals to gather their opinions to ensure the safety of everyone. Moreover, [PERSON] et al. [21] expounded on how the TPB can amplify the intention of students to prepare for campus threats in the perception of danger. It was mentioned that partaking in emergency response training is highly encouraged to respond when campus threats strike efficiently. Moreover, it was found that investing in the implementation of informed emergency preparedness messages can help minimize perceived danger on school grounds. In accordance with the scope of the study, the safety concerns when it comes to the perception of an individual should also be covered. One theory that could be used is the Protection Motivation Theory (PMT); the PMT is a framework developed by [PERSON] in 1975 to understand the impact of fear appeals [22]. [PERSON] [23] stated that there are three components of protection motivation: (1) noxiousness/severity of threat, (2) probability of event occurrence, (3) efficacy of recommended response. However, [PERSON] and [PERSON] [24] noted self-efficacy expectancy as a fourth component of the theory as it also directly influenced intentions while interacting with other variables of the theory. Subsequent research has typically used PMT as a framework to develop and evaluate persuasive communications or as a model to predict health behaviors. Although frequently applied to health-related behavior, this theory was also applied in other areas, such as protective actions taken in response to threats of danger (e.g., natural disasters, criminal victimization). [PERSON] and [PERSON] [17] discussed how the PMT showed how knowledge of dangers raised concerns about criminal victimization, resulting in the use of protective measures as a coping response. It states that for individuals to protect themselves and their property, they decide to use protective measures to make them feel safer. These protective measures vary from weapons (e.g., guns, knives, pepper sprays) to physical abilities (e.g., martial arts or any self-defense classes). Similarly, the study of [PERSON] et al. [25] found that understanding the threat risk and its severity affected their coping measures. Therefore, many individuals more prone to criminalization feel the need to purchase and carry self-protection devices such as mace and pepper spray. This study aimed to classify the factors affecting the purchasing intention of self-defense tools analyzed using a machine learning algorithm. Specifically, factors under the TPB, such as perceived behavioral control, subjective norm, and attitude, were analyzed with other factors, perceived risk, self-efficacy, and perceived security under the PMT. The nonlinear relationship of purchasing intention factors was simultaneously analyzed, similar to the study of [PERSON] et al. [26] and [PERSON] et al. [27; 28]. The results of this study would be most relevant to entrepreneurs as they would determine why an individual may purchase their self-defense goods. Knowing the consumers' perception towards the said products may help entrepreneurs to market their product more effectively and innovate it to suit the consumers' needs. Consequently, this would lead to more innovative self-defense tools or modified safety measures for criminal threats.