Factors influencing scientific reasoning ability in junior secondary students: Examining gender and grade-level predictive differences

• Scientific reasoning ability (SRA) plays a crucial role in enhancing science education and developing analytical skills among junior secondary students. • This study examines the predictive effects of science achievement, mathematics achievement, spatial ability, reading comprehension, and interest in science on SRA. • Data from 2261 junior secondary students indicate that all predictors, except mathematics achievement, significantly influence SRA. • The predictive relationships vary across grade levels and between genders, with stepwise regression analysis revealing interactive effects. • Science achievement is identified as the strongest predictor of SRA, followed by spatial ability, across both the overall sample and specific subgroups. Scientific reasoning ability (SRA) plays a critical role in advancing science education and cultivating analytical skills among junior secondary students. This study investigates the extent to which five key factors—science achievement, mathematics achievement, spatial ability, reading comprehension skills, and interest in science—predict students' SRA. A sample of 2261 junior secondary students was assessed, and multiple regression analyses revealed that all variables, except mathematics achievement, were significant predictiors of SRA. The strength of these predictive relationships varied across grade levels and gender groups. Stepwise regression analysis further indicated that gender and grade level interactively impacted the predictive strength of these factors. Across the overall sample and subgroup analyses, science achievement consistently emerged as the strongest predictor, followed by spatial ability. Our findings are discussed within the broader literature and offer important implications for science education.