In general education, learning of production tasks is important but difficult due to it requires heavy cognitive activities such as generation of ideas and synthesis of structures. We proposed a method to facilitate a production task of mathematical problem posing through learning by reproducing examples. In the proposed method, learners learn essential ideas by reproducing examples based on process information indicating how to compose them. We then conducted an experimental investigation where undergraduate students posed their own problems after learning an example by reproducing or solving it. Our previous study had confirmed that undergraduate students without learning of any examples posed many problems that had simple and inappropriate solution structures. In this study, undergraduate students who learned by reproducing the example posed many complex problems, whereas those who learned by solving it didn't do. This proved that learning of ideas for a production task is more effective when it's done through a productive activity.