In 2012, a new assessment and rating process for Australian early childhood education and care (ECEC) services was introduced, using a new National Quality Standard (NQS). The NQS assessment and rating process has similarities to observational assessment systems used in educational research, and involves similar strategies for upholding 'rigour', as defined by a positivist research paradigm. Drawing on the author's own experience supporting authorised officers to conduct NQS assessments, the paper argues that the NQS assessment and rating process also contains certain similarities to educational research conducted using a constructivist paradigm. Understandings of rigour from constructivist research—including rapport with participants, reflective practice and comfort with ambiguity—can therefore offer valuable insights into how NQS assessments can best be implemented. Although government actors maintain a preference for positivist paradigms, greater attention to constructivist paradigms may help to align the NQS assessment process with the ways of knowing valued in contemporary ECEC practice, and improve its ability to accommodate the complexity and diversity of ECEC quality. [Author abstract]