###### Abstract
[PERSON] [13] found that using AR in the real world can effectively support students to achieve situational learning and help reach their goals. AR, as a tool to develop ubiquitous learning guidance systems for EFL learners, can help to speed up their reaction time in language learning [14]. Findings have indicated a positive result of AR enhancing student learning performance [6]. Based on AR technology, [PERSON] [13] developed two learning systems, in which students can learn English vocabulary in a top-down text environment. The results showed that AR tech can facilitate ubiquitous learning, that the student may perceive a sense of existence and realism, and that learning motivation can also be enhanced. Thus, AR can allow for the innovation of educational methods. Worldwide, educational institutions and educators have been concerned with how to effectively apply AR digital technologies to certain subjects and educational aspects, as well as how to properly and objectively evaluate the learning performance of students using digital technologies to learn. Because of the popularity of smart mobile devices, incorporating foreign language teaching applications into the smartphone context provides a feasible method for education, the learning effectiveness of which has been increasingly researched [15]. According to the GSMA (Groupe Speciale Mobile Association), there are 3.6 billion smartphone users in the world, which means that, in the wireless world, 47% of the global population are mobile internet users [16]. In 2019, the Taiwan Communication Survey (TCS) also pointed out that each Taiwanese person, on average, uses a smartphone for about three hours per day; furthermore, for users aged 18 to 39, this time can be up to five hours. During this time, some users may use their smartphone as a tool for learning [17]; that is, smartphones have become popular as tools for learning [12] and, for the public, they are likely to adapt smartphones as a learning tool. In articles from 2000 to 2012 related to applying mobile devices to language learning, [PERSON], [PERSON], and [PERSON] [18] found that, during that period, PDAs were used as tools for learning. The most common related research topic focuses on feedback from elementary school to college students, in terms of the aspects of technology and linguistic competence; in which, English learning is the most common topic. Based on EFL-related theses, [PERSON] et al. [4] proved that mobile technologies can provide environments for students to interact with each other and to collaborate for learning [19; 20]. Students can attain a ubiquitous learning environment [12], while the learning context can be designed based on student capabilities and environment [21]. During language learning, the aspects of concentration, interest, and effort may be enhanced by adding entertaining elements into mobile device technologies [4; 20; 22]. In recent decades, applying digital media technology into mobile devices has been an innovative method for educators. Therefore, the combination of mobile technologies and digital media has become nearly ubiquitous in the language-learning field. [PERSON] et al. [7] also pointed out that AR is popular in learning contexts. AR techniques can mix virtual scenes and the real world together, by which an image is therefore created and the resulting hybrid world can provide amazing and interactive phenomena. Because of the popularity of smartphones, they are generally the first choice of consumers to experience AR. For example, [PERSON], [PERSON], [PERSON], and [PERSON] [5] applied AR techniques to interior design education, which was interesting for students as they could experience the scene ambiance without time delay. According to recent related literature reviews, the value of AR, in terms of positive education feedback and its concentration enhancing function, has been demonstrated [5; 13]. [PERSON] [23] considered the power of gamification its ability to produce desirable behavior changes.