This paper investigates the inferences stemming from two opposing metaphorical portraits of current educational methods (i.e., knowledge-transfer vs. knowledge construction metaphors) in contrast to the facts revealed by the actual teaching practice, and its implications for educational policy programs. To this effect, we tested the influence of the aforementioned conceptual metaphors on 100 parents with children enrolled in primary education in relation to four criteria (i.e., perceived difficulty, effectiveness, entertainment, and motivation towards teaching methods), and then conducted a study among 8 class groups (198 students) at the 6º level of primary education (i.e., between 9 and 10 years old) of 4 schools in Logroño (La Rioja, Spain) to confirm whether the inferences stemming from each of the education metaphors under consideration were mirrored in the classroom. In this experiment, students were randomly assigned to one of the two teaching methods corresponding to each of the conceptual metaphors targeted in this study (i.e., Direct Instruction for teaching is knowledge-transfer and Project Based Learning for teaching is knowledge-construction). The results show a significant gap between parents’ inferences emerging from the conceptual metaphors on education and actual students’ performance in the experiment. Both the actual learning results and the students’ perceptions about the difficulty, entertainment,and motivation of each methodology contradict the adults’ expectations based on the inferences they had drawn from these two conceptual metaphors, thus showing an unfounded prejudice of parents’ against DI’s methodologies. We discuss the implications of this research for the current debate about teaching methodologies in Spain (and other countries), and the need for evidencebased implementation of new educational policies.