This work address the preconceptions of first year engineering students about the kinematic graphs and the outcomes of a pedagogical strategy that relies on Predict -- Observe -- Explain learning method mediated by a video analysis software. The whole learning procedure was accompanied by a written material as students' worksheets which enabled a formal record of the students' conceptions throughout the process. The Test of Understanding of Kinematics Graphs was utilized to evaluate the students' preconceptions and learning gains. It was found that first year engineering students had serious difficulties in drawing and interpreting kinematic graphs. Although interpretation of graphs and the understanding of the velocity and acceleration concepts improved, the preconceptions were quite resilient.