Background. According to Godfrey’s (2016) model, a research culture consists of four elements: inquiry-based working, distributed leadership, learning organization, and systemic perspective. This model is often described in theoretical contributions (Dimmock, 2019; Godfrey, 2019), where scholars often study one element, instead of studying the elements in coherence. When aiming to map a research culture, this is problematic: (1) existing questionnaires often focus on one element, which can be operationalized from different theoretical perspectives. Merging existing questionnaires would result in a long survey with overlapping indicators, which can lead to non-response and invalid measurements; (2) the four elements can be separated but also influence each other. This study’s central research question is: "To what extent is a questionnaire, developed to map a research culture, able to distinguish the four elements of a research culture?" Sub-questions: Which model fit best matches the questionnaire data to map a research culture?" and "What are the psychometric properties of the developed questionnaire?". Method. Researchers collaborated with 27 teachers and school leaders from nine Dutch secondary schools. They followed six steps for instrument development (DeVellis & Thorpe, 2022): - scale and item development by two researchers; - revision after feedback from the research team and three teachers; - second revision after feedback from each triad of the nine schools; - first administration of the questionnaire (T=1); - analysis of validity and reliability resulting in the removal of some items; - administration of the final questionnaire (T=2). Teachers and school leaders from these nine schools completed the questionnaire during two repeated measurements (T=1: 48 items, 4 scales, 10 subscales, N=425, 9 schools; T=2: 42 items, 4 scales, 10 subscales, N=408, 8 schools). The scales are: inquiry-based working, distributed leadership, learning organization, and systemic perspective. Data were analyzed using SPSS and Mplus. Results. CFA models per scale showed acceptable to good model fit. For example, inquiry-based working at T=1: SMRM=.05, RMSEA=.07, CFI=.95, TLI=.93. Across the two measurement points, the four scales generally showed low to moderate correlations, ranging from r=.24 (p<.01) to r=.58 (p<.001), and demonstrated internal consistency, ranging from ω=.72 (systemic perspective T=2) to ω=.94 (distributed leadership T=1). Implications. The developed questionnaire shows acceptable to good model fit and strong psychometric properties: four elements can be distinguished, which correlate light to moderate. This instrument could serve as a tool for professional learning communities, consisting of teachers and school leaders, to map the research culture at their school that fosters inquiry-based curriculum development.