Replication data for: Thematic Caucuses and their definitions: a systematic review

<p><span style="font-weight: 400;">The literature on thematic caucuses and parliamentary fronts does not always agree on what defines these cross-party groups. Based on a systematic review of texts published between 2018 and 2024, following Cooper's (2016) protocol, this article aims to answer: (1) how the concepts of thematic caucuses and parliamentary fronts are defined; and (2) how these concepts are operationalized. It is demonstrated that there are three distinct approaches: categorical, collective action, and activity-based. Each has implications for the methodology used to delimit the study group, as well as differing assumptions. In other words, despite using the same terms, studies are not always referring to the same object. Furthermore, some studies use one approach for definition and another for operationalization. It is argued that, in general, works in this literature fail to recognize these differences, hindering scientific dialogue and allowing for misguided conclusions. Until conceptual mixtures are acknowledged, the contributions offered will be compromised.</span></p>