Ever since international large-scale student assessments made it possible to rank countries according to their equitability, Nordic countries have topped these rankings. Nevertheless, a decline in equity has been reported lately. However, the process of empirical enquiry that leads to specific inferences on equity partly stays obscure to education decision-makers. This unawareness of the boundaries of specific methodological and analytical approaches may lead to wrong interpretations and policy implications. Therefore, our aim is to discuss and empirically illustrate how the array of choices taken throughout the research process, from equity conceptualization and operationalization to its measurement, may affect the inferences on educational equity for Nordic countries. Our sample includes fourth- and eighth-grade students from Norway, Sweden, Denmark and Finland who participated in TIMSS 2015. We applied two-level multigroup regression models within the structural equation modelling framework to investigate the sensitivity of the countries’ level of equity to: (a) operationalization of the socioeconomic status measure; (b) operationalization of equity or, in other words, the method of analysis employed (e.g., bivariate analysis versus univariate); (c) single-level against multilevel analytical approaches; (d) the grade/age of students; and (e) the choice of the learning outcome across subject domains. Prior to the analyses, we estimated the comparability of SES as a latent construct between Nordic countries. Our results confirmed that some of the most common choices to measure educational equity do matter. Thus, we would encourage a researcher to report elaborately on the research process and inform on its limitations because if interpreted wrongly, it may have unfavourable consequences for a particular group of individuals.