It is uncontroversial that the quality of democracy is closely bound up with the quality of political representation. But what exactly is political representation and how should we study it? This Element develops a novel conceptual framework for studying political representation that makes the insights of recent theoretical work on representation usable for quantitative empirical research. The theoretical literature the authors build on makes the case for changing the understanding of representation in two ways. First, it proposes to conceive representation in constructivist terms, as a practice that is shaped by both representatives and represented. Second, it treats communicative acts by representatives that address constituents and different analytical dimensions contained in them as the central categories of analysis; political representation is thus conceived as an essentially communicative practice. This Element argues that quantitative research can benefit from taking these innovations seriously, and it provides the conceptual tools for doing so.