Michaels, Sarah, Shouse, Andrew W., Schweingruber, Heidi A.. "2 Four Strands of Science Learning." Ready, Set, SCIENCE!: Putting Research to Work in K-8 Science Classrooms. Washington, DC: The National Academies Press, 2007.
Gregory Walker taught fifth grade in a predominantly low-income urban school in northwestern Massachusetts. It was his fourth year teaching, and he was still learning how to manage a classroom and how to plan and orchestrate rigorous learning activities with an extremely heterogeneous group of students. His school district was working hard to raise student achievement to meet the demands of the state tests. Over 75 percent of the students in his school were eligible for free or reduced-price lunches,
and his district was considered an “underperforming” district and was under close scrutiny by the state.
Despite these challenges, the teachers at Mr. Walker’s school were collegial, energetic, willing to open their doors to colleagues and parents, and eager to share their successes with one another. For the past several years, the school had worked hard on improving literacy and mathematics achievement with solid results. Now the school was turning its attention to science.
The school district had appointed a committee of teachers and curriculum specialists to work together for a year to come up with a recommendation for a new science curriculum. In the meantime, teachers were asked to do the best they could to meet the state’s science standards and prepare the students for the fifth-grade state test in science.
Mr. Walker’s science class used an out-of-date textbook and several old science kits that were missing some key materials. He often stayed up late at night trying to come up with interesting science activities, but he never felt he knew enough to “invent” great science lessons. He was, however, very interested in teaching biodiversity, a topic emphasized in the national and state standards, even though the topic was not well developed in either his textbook or the available kits.
Mr. Walker’s interest in biodiversity was not without foundation. He had taken a field biology course in college taught by a charismatic professor. She explained to her students that biodiversity demanded mastery of a world of details, while physics, chemistry, and the mechanistic aspects of biology more often required comprehension of core principles and the skills needed to apply them. The ability to teach biodiversity, she said, entailed knowledge of the characteristics and behaviors that distinguish individuals, species, genera, families, orders, and classes from each other. It required helping students acquire both the tools and propensities to see and characterize variation within and between species. It required a comprehensive knowledge of ecosystem types and functions. And it required an awareness of evolutionary, geological, and human history.
For these reasons, her class, even though it was offered through the biology department, was designed to teach students how to teach biodiversity. She hoped that they, in turn, would teach biodiversity to others.
Mr. Walker decided that he could apply many of the lessons he had learned during his college class