The department's approach to linguistic theory takes a primarily cognitive-functional perspective that focuses on language structure as interacting with language use. Data-driven and fieldwork methods are emphasized to support usage-based analyses of dynamic language phenomena. This orientation emphasizes the study of language typology, change, discourse, interaction, variation, interpreting, processing, and acquisition. The department is particularly concerned with the study of regional languages (especially Navajo, varieties of Spanish, and indigenous languages of the Americas) and signed languages (American Sign Language, in particular). This theoretical approach provides the foundation for effectively addressing our commitment to the application of linguistics to social concerns, including minority language maintenance and empowerment of minority communities. Thus, the department not only studies and teaches about the structure and use of language, but also encourages faculty and student involvement as advocates and participants in outreach to the linguistic communities in which we carry out research.