This study investigates the relationships of domain-general cognitive abilities and domain-specific verbal and mathematical abilities to students' educational characteristics when two theoretically grounded, but competing structural models are applied. In the standard model, a single latent ability causes interindividual differences in the corresponding measures. In the nested-factor model, interindividual differences are caused by two independent cognitive abilities: general cognitive ability and domain-specific ability. The two models were examined using data from 29,386 ninth graders. The results show that findings on the relations between domain-specific abilities and students' socio-economic status, general school satisfaction, educational aspirations, domain-specific interests, and subject-specific grades may differ substantially depending on the structural model applied. Implications for educational research and measurement as well as for students' motivational and cognitive development are discussed.