Revisiting the SciPop Scale: Measurement alignment, scoring rules, and cross‐context comparability
2026-09-08
Science‐related populism—populist attitudes toward scientific authority—has attracted growing scholarly attention. Although the SciPop Scale measures this construct, its cross‐national psychometric properties remain underexamined. Using data from the Trust in Science and Science‐Related Populism project ( N = 69,341; 68 countries/regions) and the Swiss Science Barometer ( N = 1124), we evaluate factor structure and reliability, test multigroup invariance, apply alignment for approximate invariance, and compare scoring philosophies (Bollen vs. Goertz approach) on criterion validity. We further employ multidimensional item response theory models to provide complementary item‐level diagnostics, including discrimination, threshold, item information, and differential item functioning. Results show that reliability is high and a four‐factor model fits most broadly. Full measurement invariance holds across sex, age, education, residence, political orientation, and religiosity; partial invariance appears across regions, economic development, cultural values, and regime types. Cross‐national comparability is limited but improves via measurement alignment. Different scoring methods identify different weakest dimensions. For criterion validity, Bollen‐based aligned scores consistently outperform the Goertz approach, yielding higher explanatory power in cross‐national and cross‐group analyses. Finally, we provide guidelines for researchers using the SciPop Scale and future directions for measuring science‐related populism.