As highlighted by Kepler’s laws of planetary motion, discovered in the 17th century, mathematical modeling — describing measured data using simple mathematical expressions — has provided clues to understand various physical phenomena. However, in modern science, which utilizes advanced measurement techniques and addresses complex phenomena, data that are difficult to understand are becoming increasingly apparent. Our laboratory endeavors to establish guiding principles for a data-based and unambiguous understanding of all physical phenomena. In an interactive cycle between theoretical and empirical research, we explore the mathematics of Bayesian statistics and promote understanding of complex phenomena through interdisciplinary collaboration with researchers in natural sciences and industry.