Mixed methods research in applied linguistics integrates quantitative and qualitative approaches within a single study to gain a more comprehensive understanding of language learning, teaching, or use. Rather than relying solely on numerical data (e.g., test scores, frequency counts) or interpretive insights (e.g., interviews, observations), researchers combine both to triangulate findings, explore complex phenomena from multiple angles, and address different facets of a research question. For example, a study might quantitatively measure the effect of a teaching intervention on vocabulary acquisition while qualitatively analyzing learners’ perceptions of that intervention through journal entries. This integration allows researchers to capture not only whether something works but also why and how it works, thereby enhancing the validity, depth, and practical relevance of conclusions in diverse contexts such as classroom instruction, language policy, or second language acquisition.