This study investigated the researcher-teacher interface issue by exploring second language (L2) teachers' experiences of being involved in a large instructed second language acquisition empirical study aimed at curricular changes. The study addressed two goals. First, by involving the entire teaching staff at all levels of the multisection language teaching program in the administration of the empirical study, it examined the interface at the individual and the professional level. Second, by involving the teachers in every aspect of the study, it investigated the interface at the curricular level. Participants were 27 L2 teachers of Spanish at a private research university in the United States comprising graduate students of all disciplines and full-time and adjunct faculty. The interface data were obtained via a survey with questions related to teachers' academic backgrounds, pedagogical beliefs, experiences with academic journals, beliefs regarding the present study, overall experience, and their involvement in the research project. Two teachers also participated in in-depth personal reflections. The results showed that the active participation by the teachers raised their level of awareness of the researcher-teacher and research-curriculum interfaces and also increased their overall personal and professional development as informed teachers who employ theoretically driven and empirically supported activities in their lesson plans.