Professor Zumbo is an internationally renowned research methodologist, measurement theorist, and applied statistician/mathematician. His program of research has had wide influence in psychometrics, validity theory, educational and behavioral statistics, and language testing.
Over the last 25 years his interdisciplinary program of research has emerged to have broad interdisciplinary impact and as such is well-recognized in a variety of disciplines including psychometrics and measurement, statistics, language testing, educational research, quality of life and well being, health and human development.
His research has branched to many areas in statistics, measurement, and scientific methodology. He takes a problem-solving point of view to his research in that the research is not tied to any one area of statistics or measurement. Given his scholarly background in mathematics and philosophy, he learns and integrates new areas of mathematics or new areas of philosophy as necessary to solve a new scientific problem.
As is evident from the list of publications and awards, his program of research is noted for his having addressed cross-disciplinary recurring controversial topics such as theories of measurement validity, measurement invariance, the role of levels (or scales) of measurement in statistics, and the role of hypothesis testing in empirical studies and particularly their lack of robustness to violations of assumptions. His contributions to these debates have highlighted his orientation from philosophy of science, scientific methodology, and the intersection of mathematics, measurement and statistical science.
His program of research is actively engaged in psychometrics for language testing, quality of life and wellbeing, and health and human development. This applied work, in the end, feeds his basic program of research in research methodology and measurement.
His scholarly life is driven by an immense curiosity and desire to learn, as well as a great deal of energy and commitment to learning, knowledge translation and dissemination.