Developing student self-efficacy and conceptualizing the importance of core ideas are seen as important learning areas in science education. Such core ideas can be elucidated with respect to the science discipline as well as interdisciplinary learning. Schools can be expected to promote high levels of students' self-efficacy in acquiring major disciplinary ideas and guiding students toward recognizing the importance of gaining work and life skills. This research sought to develop models describing students' gains in perceived self-efficacy and importance of work and life skills as well as indicating the relationship with both disciplinary and interdisciplinary core ideas in science education. Using a validated instrument, data were collected from Grade 8 (n = 218) (14-15 years old) and Grade 11 (n = 95) (17-18 years old) students. Models were created based on confirmatory factor analysis and parallel analysis. This research shows that there is need to make changes in secondary school studies so as to more clearly recognize a framework for both disciplinary and interdisciplinary core ideas, shown to be important for enabling students to prepare for their future life and careers.