This article reports the results of a mixed-methods approach to develop and validate an instrument tomeasure Indonesian pre-service teachers’ conceptions ofstatistics. First, a phenomenographic study involving asample of 44 participants uncovered six categories ofconceptions of statistics. Second, an instrument of con-ceptions of statistics was developed on the basis of findingsfrom the phenomenographic study. The instrument wasinitially piloted with 63 participants. Subsequently, anexploratory factor analysis involving 116 participants,followed by a confirmatory factor analysis involving 232participants, was executed, suggesting a three-factorstructure. In addition, three different types of conceptionsof statistical data were identified from the integration ofqualitative and quantitative studies. Contributions of thestudy and implications of the findings for further researchand statistics education are discussed

• Development and Validation of an Instrument to MeasureIndonesian Pre-service Teachers’ Conceptions of Statistics