The research group of Applied Linguistics in Foreign Languages from the University of Sonora in Mexico has been carrying out research for over a decade. This research group investigates processes in two areas, which are the learning and teaching of foreign languages and teacher education. As many studies have found out, in these processes the intervention of beliefs is a crucial component in the teaching and learning since students plan their learning strategies based on their own beliefs. Furthermore, studies have evidenced that not only students, but teachers and teacher educators carry out every aspect of their work based on their own beliefs about how languages are learned and how these languages should be taught. Therefore, the area of beliefs about language teaching and learning has been a research interest for this group of teacher researchers.