We studied the effective use of a guest speaker in career education in regular science education. On two occasions, we conducted classes with the aid of a guest speaker working in a science-based profession. We then investigated the effects of the experiment. During the first class, it was clear that students were able to understand the contents of the lecture and see some connection with their studies. These ties, however, were somewhat limited. Prior to the initial meeting, students had prepared a "concept map", detailing their expectations for the lesson. Before the next class, we discus...