PITTSBURGH—Stories of exciting chemistry discoveries in Scientific American and The New York Times paint a better picture of chemistry as it is practiced than do some widely used high school textbooks, according to a study by Carnegie Mellon University and the University of Pittsburgh. The findings signal that introductory textbooks could be shortchanging students, denying them exposure to the creativity of chemistry and omitting context they need to be scientifically literate citizens, according to the authors, whose results are in press at the Journal of Chemical Education.
"High school textbooks focus on teaching a set of basic tools that chemists use, but they often fail to address how those tools are used by practicing chemists," said David Yaron, associate professor of chemistry at Carnegie Mellon. "Because of this misalignment, students may leave an introductory chemistry course without a practical perspective on the field of chemistry. If one of our goals is to educate scientifically literate people who can read Scientific American and the science section of The New York Times, then we are not giving them the tools they need. We may also be missing chances to attract talented students to this important field."
Yaron and his collaborator, Gaea Leinhardt, senior scientist at the University of Pittsburgh's Learning Research and Development Center, initially set out to develop online teaching tools for the full range of introductory chemistry courses. But when they reviewed state content standards, concepts used in Nobel laureates' prize work in chemistry and articles in the science press, they found something unexpected: These sources presented activities that weren't described by the California State Content Standards for Chemistry. This significant misalignment prompted Leinhardt, Yaron and their research group, Karen Evans and Michael Karabinos, to develop a testable framework that describes activities in which chemists routinely engage. They determined that chemists explain phenomena, analyze matter to determine its chemical makeup and synthesize new substances. Chemists also have a set of tools in their "toolbox" that they use to develop explanations, conduct analyses or direct syntheses.
Using this framework to analyze two popular chemistry textbooks, they found that the textbooks focus almost exclusively on explaining phenomena and learning tools, such as the basic structure of atoms and the units needed to balance equations. Stories from Scientific American and The New York Times and 50 years of Nobel laureates' prize work in chemistry cover topics across all three activities: explaining, analyzing and synthesizing.
"Using this approach, we can analyze scientific text and base our curriculum decisions on objective information about what concepts are important to convey in introductory chemistry. This allows us to go beyond asking experts for their opinions on what should be taught," said Yaron.
"Textbooks tend to follow a bottom-up approach to learning chemistry. This approach involves teaching abstract concepts and tools before discussing their use in the practice of chemistry, which results in students learning bits of unconnected knowledge that are rarely usable, let alone memorable," said Leinhardt.
To remedy this situation, Yaron, Leinhardt and colleagues are using the proposed framework to direct how they develop curriculum. For example, they create scenario-based activities that help students see interesting real-world applications of key concepts and approach chemistry more like practicing scientists.
"Although the structure of many courses assumes otherwise, we believe that introductory-level students can reap the benefits of working on real-world applications before they master most of the basic notational procedures, in part through the use of simulations and scenarios," said Yaron.
One scenario-based activity developed at Carnegie Mellon, "Mixed Reception," allows students to use concepts such as formula weight, stoichiometry (the math used in chemistry) and the scientific method to solve a murder mystery. To date, hundreds of high school teachers have requested CDs of this scenario.
These scenarios are only one component of a suite of activities they have designed to enhance chemistry education for students and teachers. A collection of scenario-based learning activities, virtual labs and concepts tests can be found at www.chemcollective.org. Yaron and colleagues also have partnered with Carnegie Mellon's Open Learning Initiative (OLI), a cutting-edge program to develop online versions of high-demand, introductory-level college courses, including an introductory chemistry course. The OLI chemistry course will be evaluated at the new Pittsburgh Science of Learning Center, a joint Carnegie Mellon-Pitt education research center that was launched in 2004 with a $25 million grant from the National Science Foundation.
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