At the intersection of pedagogy and mathematics lies the field of mathematics education research. The field is quite broad in scope as this intersection is quite large. Researchers might be interested in how students conceptualize transformations in linear algebra, different approaches to teaching proof by contradiction, curriculum design in an algebra course, the role of technology in middle school classrooms, or the influence of factors such as race or gender on the learning of mathematics. Researchers use a mixture of qualitative (interviews, ethnographies) and quantitative tools (data science, statistics) to explore phenomena from small scales (individual students) to large (school districts, states). Overall, the goal is to improve mathematics instruction using the tools of academic research.