Studies indicate that qualitative understanding of phenomena, as expressed in students' explanations and predictions, is not satisfactorily achieved by most high schools and college graduate students. Even after instruction of basic domains such as introductory mechanics, students¿ conceptual understanding of topics remains almost unchanged. We argue that it can be done by unpacking the difficulties that are faced in this domain and by developing a method that responds to these problems discussed above. More specifically, we suggest that it is advisable to choose tasks that focus on explaining and predicting relevant everyday situations in the chosen domain (mechanics), and to provide students (and teachers) with conceptual basis as well as cognitive tools to carry out such tasks. These tools are derived from a qualitative problem solving strategy for explaining and predicting phenomena that deal with interactions, forces and motion. We also argue that teachers¿ professional development in this domain is the key to any future change and implementation of new methods for advancing the teaching of physics.