## 2 Hypothesis Development
### Perceived Behavioral Control  
Perceived behavioral control reflects the beliefs about the acquisition of required abilities, resources, and opportunities, or the perception of possible internal and external factors that may hinder behavior execution [15; 45]. In this research, perceived behavioral control includes the perception of the internal and external constraints of individual teachers when implementing STEM education. Research has shown that perceived behavioral control is an important determinant of intentions [25]. For example, through empirical investigations, [PERSON] and [PERSON] [19] verified that perceived behavioral control of a higher level was related to stronger STEM instructional intentions. Therefore, the following hypothesis was proposed:  
**Hypothesis 3:**: _Teachers' perceived behavioral control over STEM education has a significant impact on teachers' intentions to engage in STEM education._  
The DTPB model divides perceived behavioral control into internal and external constraints, which specifically indicate self-efficacy, resources, and technical factors. In this research, self-efficacy reflects teachers' self-evaluation of their abilities to implement STEM courses, indicating the degree of confidence in implementing STEM education. Greater self-efficacy leads to higher behavioral intentions [25; 46]. [PERSON] [28] found that self-efficacy was the strongest predictor of teachers' intentions. Convenience refers to technology, resources, and other objective factors available to teachers when implementing STEM courses. A lack of convenience may negatively affect the behavioral intentions of teachers [25].  
Readiness is a significant predictor of an individual's propensity to use new technologies [47; 48]. Teachers' preparation of knowledge and their self-efficacy in STEM are the key to successful STEM implementation [35]. Furthermore, for different topics such as technology applications, jobs, careers, teaching, and learning, relevant research has confirmed that there is a significant correlation between the degree of readiness and self-efficacy [49; 50; 51]. Although no research has been conducted to show that the degree of teachers' STEM readiness directly affects their teaching efficacy, it can be deduced from the relevant literature that the former could significantly predict the latter. To reduce concept repetition and simplify the models, this research chose the dimensions of cognitive and behavioral readiness from the degree of readiness to investigate and discuss whether these two could predict the self-efficacy of teachers. The cognitive readiness of teachers refers to the improvement of thinking and the ability to make cognitive choices to solve STEM problems or complete STEM teaching tasks [33]. Behavioral readiness refers to the attitudes towards STEM, changing emotional reactions, and the changes that can be seen in STEM teaching behaviors [36].  
Based on this, we proposed the following hypotheses:  
**Hypothesis 3a:**_The self-efficacy of teachers' STEM education has a significant influence on perceived behavioral control._  
**Hypothesis 3b:**_Facilitating conditions of teachers' STEM education have a significant influence on perceived behavioral control._  
**Hypothesis 3c:**_The behavioral readiness of teachers' STEM education has a significant influence on self-efficacy._  
**Hypothesis 3d:**_The cognitive readiness of teachers' STEM education has a significant influence on self-efficacy._  
**Hypothesis 3f:**_The cognitive readiness of teachers' STEM education has a significant influence on self-efficacy._