In recent years, researches had shown that the development of problem solving skill became important for education, and the educational robots are capable for promoting students not only understand the physical and mathematical concepts, but also have active and constructive learning. Meanwhile, the importance of situation in education is rising, since studies had declared that knowledge's acquirement always occurs when people experience in a particular situation. The situation is indivisible from one's learning activities. In this study we tried to integrate four theories: the anchored instruction which originated from the situated cognition; the web-based learning which is the main way of searching information today; the problem-based learning which focus on development of students' problem solving skills; and the flow theory which is the best way to understand motivation.