We face a real crisis in science education in America. Representative Bart Gordon of Tennessee, chair of the House Committee on Science and Technology, has warned that countries such as China and India will trample the U.S. economy in the near future without major improvements in teaching. Indeed, our schools are falling behind. In the 2006 Program for International Student Assessment (PISA)—a respected measure of achievement around the globe—the average science score of U.S. 15-year-olds dropped below that of teens in 28 out of 57 participating countries. (In math, U.S. students fared even worse, lagging behind their peers in 34 nations.)
Despite decades of reform, America has made only modest gains in the science classroom, particularly in high schools. Two recent reports from the National Research Council (NRC), however, offer novel strategies. Entitled Taking Science to School and Ready, Set, Science!, they call for changes in the way science is taught beginning in elementary school. Unlike previous recommendations, the new suggestions reflect recent findings from neuroscience and psychology about how young children think and how they acquire knowledge.
Whereas past reform has aimed primarily at placing the U.S. first among other nations, the latest reports offer a well-defined goal of science proficiency: students must be able to know, use and interpret scientific explanations of the natural world; they must be able to generate and evaluate scientific evidence and explanations; they must be able to understand the nature and development of scientific knowledge; and they must be able to participate meaningfully in scientific activities and discourse.
These four interrelated targets weave a “science as practice” approach, widely endorsed by education researchers. K-8 instruction needs to present science as a dynamic process. Currently most schools package science into two parts: the step-by-step scientific method and a collection of unproblematic facts. As a result, most children hold an absolute view of what they see as “the truth” and believe most knowledge results from direct observations. As these pupils grow, many never realize that science is an exercise in building and revising theories. But all students—not just those who intend to pursue a scientific career—should learn how scientific knowledge is constructed. Basic scientific literacy will be mandatory for anyone hoping to fully participate in our future society as a responsible adult.
Rethinking How Children Learn
A long-standing question in education concerns what students can learn at various ages. Until recently, educators and psychologists assumed that age alone determined this learning capacity. Abstract thinking, they believed, took considerable time to develop, and so with younger classes, teachers often focused on memorization over understanding. This limited view of children’s cognitive abilities grew from a 1958 study, The Growth of Logical Thinking from Childhood to Adolescence. In it, Jean Piaget, the father of child psychology, and his colleague Brbel Inhelder asserted that no form of instruction could hasten the onset—typically at age 12—of logical thinking.
More contemporary research, though, shows that children do possess the capacity for scientific reasoning long before age 12. In a 2004 study of third and fourth graders, David Klahr of Carnegie Mellon University and Milena K. Nigam of the University of Pittsburgh demonstrated that, given the appropriate instruction, young children can grasp abstract concepts such as controlled experimental design. Even earlier, from infancy to preschool, children observe and interact with the world around them: they start to understand how objects move and how creatures live; they realize that different people hold different ideas, and so forth. In certain situations, they can differentiate cause and effect, design experiments, and make use of models and symbols.
After children enter elementary school, their skills advance rapidly. Educators previously credited this leap solely to cognitive development. With greater maturity, children possess longer attention spans, greater self-discipline and faster processing speeds. But maturity is not the only force driving learning. Encouragingly, researchers have found that progress is largely contingent on a child’s prior learning experiences. The quality of these educational experiences is the key, not the child’s age or developmental stage or how early or late he or she starts school.
These findings affirm what learning theorists have long recognized: students master an idea more readily when they have some foundation of knowledge to build on. Researchers are now actively pursuing so-called learning progressions, the conceptual paths students take as they move from a simplistic to a sophisticated view of some subject. Seminal studies by Vanderbilt University professors of science education Richard Lehrer and Leona Schauble, for example, have examined how students develop an understanding of topics such as density, growth and motion using model-based reasoning. Working with children across several elementary school grades, they have observed a steady advancement in the pupils’ ability to create models from straightforward depictions to more symbolic and mathematically valuable representations.
Given a solid foundation, teachers can easily build out extensions. When a child already has some idea about animals, for example, it is not difficult to introduce, say, the platypus. Other conceptual additions come only as children gain knowledge in other areas and in their ability to use mathematical representations, symbols and models. Some new ideas are so counterintuitive that students need to shift their entire way of thinking. Pupils must also develop a sense of metacognition and notice when their understanding varies from evidence generated in the classroom or from scientific theory. But the pattern remains the same: the most successful route to mastery in any subject follows a spiral path, in which students regularly revisit and refine their conceptual underpinnings.
More Effective Teaching
Based on these insights, the NRC reports advocate a science curriculum that revisits topics at increasing levels of sophistication. Students deepen their understanding of a topic—and hone their science abilities—across many grades. The authors criticize current standards on several fronts: the curricula lay out too many discrete pieces of knowledge, with no hierarchy or meaningful sequencing; they separate skills from content; and they overemphasize methods. Studies such as the PISA that compare U.S. curricula with those of other countries underscore the point: countries that teach fewer topics overall produce higher scores. To that end, the new vision proposes that U.S. science educators focus on core topics, such as atomic-molecular theory, evolutionary theory, cell theory, and force and motion.
In Atlas of Science Literacy, the American Association for the Advancement of Science has attempted to map out what facts should be linked to such core concepts in science, grade by grade, so that students eventually assemble a complete, detailed view. Curriculum writers are using these maps to develop lesson plans that advance students through carefully designed learning experiences, not simply the passing of time. The most effective learning experiences gradually expand both the knowledge and the skills needed to engage with science authentically—that is, in a manner akin to how scientists do science in the real world.
To actually do science in the classroom like a scientist calls for a wide variety of learning experiences, including problem- and project-based lessons and considerable social interaction. As is the case among scientists, argumentation and discourse help students to challenge and sharpen one another’s ideas and to articulate and examine their own. Pupils must learn to speak and write using the specialized language of science, and they must be versed in the use of models and other mathematical tools. Kathleen Metz of the University of California, Berkeley, has demonstrated that even first graders can work in pairs to conceptualize and implement a study of their own design. Interviews showed that nearly all the children could express the aim, method and results of their study. Half of them could also analyze their design and devise ways to improve it.
Because children lack experience, though, they need carefully considered help from teachers to harvest the fruits of their independent investigations. For most learners, only limited learning results from totally free explorations or, at the other extreme, cookbook-type guidance. Teachers must continuously grasp those critical times to provide instructional scaffolding. This scaffolding—which can take many forms, including oral feedback, supplementary handouts and software tools—enables students to reach what would not be possible through cognitive development alone.
It is essential for teachers to connect what pupils already know and guide them toward becoming science-informed citizens. Teachers should recognize each student’s prior knowledge, respect the diverse backgrounds from which they come and, even more important, employ that information to make their class’s scientific practices richer and more meaningful. To have the best chance at assisting children where and when they need it, the reports advise teachers to implant assessment into the learning process. By constantly probing their pupils’ understandings, teachers are being afforded the best opportunities to connect with them.
Despite its promise, the new vision presents significant challenges. The cost of providing in-service teachers’ professional development and redesigning classroom or laboratory space—as well as the expense of additional materials—may prohibit disadvantaged regions from adopting the proposed changes. Also, although no one disputes the value of developing spiral curricula that focus on fewer core topics that are revisited over time, selecting those topics could prove contentious. It will also take serious coordination to implement such a curriculum: Will teachers have enough opportunity to interact with peers across schools and grades to ensure a seamless progression through any one topic? Will adequate class time be available for science instruction, given the strictures of the No Child Left Behind legislation? Are there enough science teachers available? In the proposed curriculum, science teachers play a central role—one that demands extensive planning and improvisatory skills, as well as vast knowledge, not only about science but also about the cultures and environments in which their students live.
Finally, the proposed curricula can succeed only if students are motivated to learn. If they lack the inherent interest or the support needed to sustain their interest, they will not reap the benefits of the newly designed experiences. According to feedback from teachers in the field, this issue may prove most difficult to surmount. Even though scientific thought processes are natural to most children, the NRC documents report that students often have negative attitudes toward science, based on poor academic experiences or inaccurate views of how it works. In some cases, pupils simply do not want to expend their mental energy on a subject they see as irrelevant to their life. But that notion could not be farther from the truth. As we face such dire threats as flu pandemic and global climate change, our very future hinges on how well the next generation learns science.