Global Patterns in Learning NMR Spectral Interpretation: Analysis of 1.3 Million Answers Submitted to NMR-Challenge.com

Abstract Nuclear magnetic resonance (NMR) spectroscopy is a fundamental analytical technique in chemistry education, yet developing proficiency in spectral interpretation requires an extensive amount of practice. Online learning platforms provide opportunities for students to train these skills while simultaneously generating large data sets that can be used to analyze learning behavior. In this study, we analyze more than 1.3 million answers submitted to NMR assignments on the educational Web site NMR-Challenge.com between December 2024 and August 2026. The platform provides assignments at six levels of difficulty involving either one-dimensional (1D) spectra or combinations of 1D and two-dimensional (2D) spectra. Submissions originated from 128 countries, with 61 countries contributing more than 1000 attempts each and accounting for more than 99% of the data set. The majority of submissions (approximately 92%) involved assignments with only 1D spectra. Across these assignments, the overall success rate was 46%, with country-specific success rates ranging from 29% to 54%. The highest overall success rates were observed for the Czech Republic, Hungary, Cameroon, Saudi Arabia, and Vietnam. Attempts to correlate success rates with national indicators revealed only a weak correlation with PISA science scores. The results demonstrate both the global reach of the platform and the potential of large-scale educational data sets to provide insights into the acquisition of practical spectroscopy skills. However, the absence of user-level demographic information limits the interpretation of country-specific differences, highlighting the need for future studies combining large data sets with more detailed educational context.