BASIC APPROACH For introductory courses in Environmental Science, Environmental Studies, and Environmental Biology. Prentice Hall's Learning System Series Developed for one-semester general education courses, the Prentice Hall's Learning System Series provides an alternative to traditional texts—a series of lower cost, shorter texts with closely connected web applications. Flexible, streamlined, and efficient, each element in the System Edition is designed to maximize the advantages of its medium and correlate to students' course activity.