The current paper investigates the extent to which teachers' approaches to teaching (the Information Transmission/Teacher-Focused (ITTF) approach, and the Conceptual Change/Student-Focused (CCSF) approach) can be explained by contextual variables (class size, perceived control of the teaching process, relationship with the students) and teacher variables (gender, teaching experience and pedagogical training). The hypothesized structural equation model (SEM) has been tested with two different samples (calibration and validation ones). Seven hundred ninety five teachers from high school science department enrolled in the study. Data suggest that teachers are most likely to use a teaching approach targeting knowledge building specially when they a. have experienced a longer pedagogical training, b. have more control over the teaching process, c. have been teaching for more years, d. develop a personal relationship with their students and, e) have a smaller number of students to teach.1812546