The purpose of this study was to investigate science learning in an informal setting in order to further develop the theory of science centre education as a form of informal education. The main focus of the study was to find more explicit evidence for earlier findings concerning intrinsic and instrumental motivation of school students visiting science centres. The subjects of this study visited a science centre exhibition once a month during a school year following a plan complementing the science curriculum of the school and exhibitions of Heureka Science Centre, Finland. The students' motivation was assessed by the motivation (intrinsic/instrumental) test and two cognitive tests (Raven applied, Mecano). The tests were administrated before (pre) and at the completion (post) of the visit program. Students in the program were organised into three treatment groups of junior high school (1) ordinary students, (2) learning difficulties students, (3) gifted students, and a control group. The results of the standard tests were compared with the ordinary, learning difficulties and gifted students groups and a control group. Results indicate that the intrinsic motivation of learning difficulties and gifted groups grew during the project. The instrumental motivation of all the croups visiting the science centre grew, while the instrumental motivation of the control group decreased. Using programs, such as the linking of schools and science centres together in meaningful learning initiatives, teenager' decreasing motivation for learning can be minimised. No statistically significant gender differences were found. However, the quasi experimental design allowed many background variables of school and home to be uncontrolled. Findings suggest that the students' situation motivation can be ennobled into intrinsic motivation through well organised programs linking schools to the informal learning settings of science centres.