Pre-conceptual schemas are models for representing knowledge about any domain. Pre-conceptual schemas have been used for teaching software engineering for ten years in the National University of Colombia, since they are the basis for the so-called UNC-Method, a software development method created by researchers of such University. Several generations of software engineers have been taught with such models and, consequently, in this paper we survey some of them for gathering the lessons learned from such experience. Results are clear about the advantages and usage of pre-conceptual schemas for teaching software engineering. We also summarize such results and provide feedback for future development of pre-conceptual schemas.