Kenneth Zellner teaches fifth graders at Kernsville Elementary School in Orefield. "Elementary students," he says, "when engaged in science instruction, should be doing the work of scientists using the tools of scientists and discussing the current impacts of science on society."To advance that goal, Mr. Zellner has painstakingly developed an activity-based science program which has been adopted by 150 educators. At Kernsville Elementary School, Mr. Zellner is responsible for the planning, construction and maintenance of an on-site environmental laboratory facility. He has also worked with over 30 student teachers in his classroom, and he has helped colleagues "improve their instructional techniques through the process approach, demonstrations and utilizing the outdoors to make learning relevant."Mr. Zellner is also a 1992 recipient of the Presidential Award for Excellence in Science and Mathematics Teaching.