## 1 Introduction  
Many students as well as practitioners, researchers, and teachers resort to using YouTube as a learning tool, and many educational and training institutes offer their educational materials through YouTube. YouTube as a platform is available to everyone and anyone. Knowledge seekers may use such a platform to educate themselves as an alternative to face-to-face lectures for many reasons: availability, ease of use, etc., and, in fact, many will adopt such a source as an alternative. The question is what are the factors that influence such adoption of YouTube as a learning tool? This research adopted an expanded information adoption model (IAM) to study this case and used academic achievement as a motivation since [1] studied the factors influencing students' web-based learning performance during the COVID-19 pandemic. That study stressed the influence of learning anxiety, attitude, and motivation on web-based learning, and found that motivation is the essential factor. YouTube has many advantages: visual and auditory facilitation of knowledge transfer, it accommodates learning pace, and can be used as a complementary learning resource for educators. YouTube allows interactivity among users [2], enhances the understanding of course content, meets learners' expectation, encourages self-directed learning, and provides a free source of learning, and users can create, share, comment, and develop their own YouTube content with lifelong learning [3]. The objective of this research is to study the influence of YouTube as a learning tool on academic achievement within the scope of the extended information adoption model that includes information usefulness (credibility, language), quality (intrinsic, contextual, accessibility), and adoption perspectives. Furthermore, the research was conducted in a bilingual academic environment. The motivation of this research is the following: YouTube is used as a learning tool in many fields from accounting in [4] to anatomy, as in [5]. In fact, according to [6], a study conducted by [5] \"examined the application of YouTube videos in an anatomy course and found that 98% of the students utilized YouTube as an online information resource and 92% agreed that the tutorial videos on YouTube were helpful\". As such, the previous study only reflects the importance of and motivation to conduct this research. The credibility of knowledge sought from YouTube is very important [7], in fact some students rely on YouTube as source of information [8; 9; 10], while others try to measure the cognition value of YouTube education videos [11]. The importance of this research stems from the above findings. Teachers, practitioners, and researchers can use the findings of this research as a support. Teachers can learn more about delivering knowledge by learning from popular YouTube teachers. Educational institutes may share knowledge from each other. Publishing houses may accommodate students' needs by providing YouTube channels just as in e-textbooks [12]. Researchers and practitioners can even develop web services [13]. The current study makes a significant contribution by examining a proposed model that includes five independent factors, three intermediate factors, four moderating factors, and one dependent factor. As a result, the research attempted to take a comprehensive look at the influencing factors of YouTube. However, to the best of the researchers' knowledge, no research was found to include all of these factors within one research scope of YouTube, nor has the proposed model been examined in the bilingual context. The empirical results offer several key findings. Academic achievement (AA) is influenced by information adoption (IA) of YouTube as a learning tool. Information adoption (IA) is influenced by information usefulness (IU). Source credibility (SC) and information quality (IQ) both influence information usefulness (IU), while information language (IL) does not. Information quality (IQ) is influenced by the quality of intrinsic, contextual, and accessible information.