Data Sources and Citation Metrics
The 5th edition of the Research.com Best Materials Science Scientists in Japan Ranking is founded upon a robust data aggregation framework. Primary sources of bibliometric data include OpenAlex and CrossRef, supplemented by multiple other reputable data sources to ensure comprehensiveness and accuracy. The citation-based metrics utilized in the ranking were compiled on January 12, 2026. A scientist’s position in the ranking is determined by their D-index (Discipline H-index), a specialized metric that quantifies research impact exclusively within the examined discipline, thereby reflecting a focused scholarly contribution in Materials Science.
Scope of Research and Qualification Criteria
The ranking analyzed a total of 279,971 scientist profiles drawn from a diverse set of bibliometric data repositories spanning all academic disciplines. Within this extensive dataset, 817 scientists specializing in Materials Science were identified and examined specifically for this ranking. To qualify, a researcher had to demonstrate a D-index of at least 40, with the majority of their tier publications firmly situated in the field of Materials Science. Additionally, awards and professional achievements pertinent to Materials Science were factored into the evaluation. The D-index threshold is adaptively set in increments of 10 relative to the estimated total number of scholars in each discipline, ensuring inclusion of the top 1% of leading experts. Furthermore, a proximity criterion was applied, requiring that the differential between a scientist's general H-index and their D-index remain within 30%, underscoring discipline-specific impact rather than generalist metrics.
Verification and Validation Practices
The team behind this ranking acknowledges that raw bibliometric data alone cannot serve as an absolute measure of scholarly output. Therefore, all scientist profiles underwent meticulous manual verification and were cross-correlated with publications found in a broad range of reputable academic sources. While the number of papers published in prominent journals and participation in distinguished conference proceedings do not influence the final ranking position, these factors are recognized as valuable secondary indicators of a researcher's substantive contribution to the discipline.
The ranking positions are primarily established using each researcher's D-index, calculated from data aggregated by OpenAlex and CrossRef—two of the most prominent and widely trusted bibliometric databases accessible to the research community. To review the detailed methodology underpinning this ranking, please visit our methodology page.
Research.com’s Mission
Research.com is driven by a clear mission: to motivate researchers, industry leaders, and policymakers worldwide to explore and understand the trajectories of leading experts. By revealing who the preeminent scientists are within specific disciplines, countries, and institutions, we aim to foster greater connectivity and awareness within the scientific community. This ranking serves as a trusted resource, providing transparent, rigorously vetted insights that support informed decisions in academia, research funding, and policy formulation.
