Analogies are known to foster concept learning, whereas discovery learning is effective for transfer. By combining discovery learning and analogies or similarities of concepts, attractive new arrangements emerge, but do they maintain both concept and transfer effects? Unfortunately, there is a lack of data confirming such combined effectiveness. This experimental study involving 280 young students in the domain of physics showed that adequately structured similarities between mechanics and geometry improves conceptual performance (perception of functional relations) by as much for discovery learning as for conventional teaching texts with questions. Adequate structures were provided following Glynn's teaching with analogy model. The learning form had no significant impact on concept performance. The effect of similarity increased when the level of difficulty of the treatment was raised. These results were found using a 2x2-factorial design. A qualitative questionnaire provided individual information about the usefulness of similarities and about learning strategies of the participants.