Personal teaching efficacy is associated with a teacher's effectiveness in the classroom. To enhance this efficacy in a computer-simulated training program, both personal traits and guided practices need to be considered concurrently. In this study, it was hypothesised that the interactive effects from the coupling of personal traits with guided practices would be a reliable predictor of the degree of improvement in personal teaching efficacy during computer-simulated training. One hundred and seventy-eight preservice teachers completed an interactive teaching experience via the "Computer Simulation for Teaching General Critical-thinking Skills" in which guided practices were integrated via specially designed teaching sequences and loops. The findings suggest that intrapersonal intelligence, critical-thinking dispositions and a judicial thinking style are related to self-awareness, analytical learning and reflective thinking and that in this study, these personal qualities seemingly interacted with guided practices, which resulted in reflective teaching and mastery experience. This, in turn, may very well have brought about improvement in the preservice teachers' personal teaching efficacy during the computer-simulated teaching.