The aim of this paper was to describe the changes in one student's ideas about force and one-dimensional motion concepts and portray the relevant metaconceptual processes that she engaged in during the implementation of metaconceptual teaching interventions. Metaconceptual processes involves metacognitive processes that are directly acting on or related to individuals' conceptions, mental models or elements of their conceptual ecology. Several types of instructional activities including poster drawing, concept mapping, group debate, journal writing and group and class discussions were used to activate students' metaconceptual processes. The findings of the study indicated that the student changed all of her alternative ideas that were assessed before the instruction with scientifically accepted conceptions following the instruction. The findings also showed that the student engaged in several types of metaconceptual processes ranging from simple awareness of ideas to more sophisticated metaconceptual processes, such as metaconceptual monitoring and evaluation. The findings strengthen the claims about the positive impact of metaconceptual processes on changing students' conceptions of physical world. Copyright © 2007 by Moment.