A curriculum project can be positively or negatively influenced by the environment of the classroom in which it is implemented. Analysis of the perceptions of students, teachers, and external observers has allowed us to study the influence of classroom environment in the implementation of an innovative project in science education. The main conclusions indicate that even though the global evaluation is positive, more so among teachers than among students, there are differences between the perceptions of the participants, probably due to differences in interests and needs. Moreover, in the classroom environment, the teacher and the actual dynamic and spatial organization are of great importance, and it can be difficult to maintain interest or to achieve a satisfactory evaluation on the part of those students whose academic performance is lowest.

A curriculum project can be positively or negatively influenced by the environment of the classroom in which it is implemented. Analysis of the perceptions of students, teachers, and external observers has allowed us to study the influence of classroom environment in the implementation of an innovative project in science education. The main conclusions indicate that even though the global evaluation is positive, more so among teachers than among students, there are differences between the perceptions of the participants, probably due to differences in interests and needs. Moreover, in the classroom environment, the teacher and the actual dynamic and spatial organization are of great importance, and it can be difficult to maintain interest or to achieve a satisfactory evaluation on the part of those students whose academic performance is lowest. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 655–671, 1998.