This paper presents the results of three years of development and evaluation of a CD-ROM/Web hybrid simulation known as Brownfield Action for an introductory environmental science course at an independent college for women in the northeastern United States. Brownfield Action is a simulation that provides a learning environment for developing the skills of an environmental site investigator by placing students in a virtual town and asking them to serve as consultants to a real estate developer who wants to avoid purchasing potentially contaminated land. Students must become actively involved in the lecture and laboratory in order to succeed. They work collaboratively with a partner in order to reach a valid conclusion. Results are summarized as follows. Students learned more and in greater depth using Brownfield Action than in previous years without it; student work looked more authentic and professional, closer to what would be expected of a professional performing these tasks; students appreciated how the simulation contributed to their understanding of the material; Brownfield Action was successful in enhancing the scientific literacy of students, facilitating their construction of new meaning based upon what they saw and experienced, and enhancing practices leading to increased student learning; students' abilities to construct new meaning based upon what they saw and experienced were expanded; students found the content useful and the simulation a good way to learn it; more staff development is necessary to foster the teaching strategies needed for a true discovery process and to build comfort with technology; minor technical glitches created levels of frustration that interfered with its ability to meet its educational potential, however students gave high ratings to other features of the technology, and in particular, eight out of ten students noted the ease with which it was possible to move through information in each of the sections of the simulation. In all, the project has proved successful in providing students with a more integrated science experience than in traditional classrooms. (AEF)