Project 2061

March 2012

Getting Middle Schoolers Ready for High School Biology

Although chemistry and biology are usually taught in different courses and even in different grades, more than 260 students in Colorado, Maryland, and Washington, DC, have discovered that learning them together can help make some important ideas much clearer. As participants in the 2011 pilot testing of a new four-week curriculum unit being developed by AAAS Project 2061 in partnership with BSCS, these students had a chance to try out some new approaches to learning about chemical reactions in both physical and life science contexts. Test results, while still preliminary, have shown significant performance gains for students in all three sites and from a diverse range of backgrounds.

Not only did the students learn more about fundamental chemistry and biochemistry ideas, they also provided valuable feedback to the research team on all aspects of the new unit, Toward High School Biology: Understanding Growth in Living Things. For example, students were particularly intrigued by activities in which they used LEGO^® bricks and ball-and-stick models to show that while atoms and molecules rearrange during chemical reactions to create new substances, the atoms themselves are not lost or gained. And, indeed, engaging students in the use of multiple models to represent phenomena involving both simple and complex chemical reactions is one of the main ways in which this unit differs from those that are currently in use.

New Approach Needed

Many U.S. middle school students struggle to learn the underlying concepts related to phenomena that involve mass changes during chemical reactions, including such everyday phenomena as the rusting of a metal bicycle or the production of muscles in humans. Nevertheless, having a strong understanding of these concepts is essential, not only for advanced chemistry studies but also for the study of life itself.

According to experts in the field, modern biology has become much more chemical in nature, and the National Research Council reports that “… molecular biology, genetics, cell biology, proteomics, physiology, microbiology, neurobiology, agriculture, and many other divisions of biology are now using chemistry as a major part of their language and their research” (2003, p. 136). Most textbooks and instructional strategies being used in the U.S. today have not adapted to this new reality and are not getting the job done. For example, in Project 2061’s own assessments of students' science knowledge, fewer than half of the middle and high school students were able to identify linked carbon, hydrogen, and oxygen molecules as food for plants or knew that the sugar molecules in plants are the products of a chemical reaction.

With a grant from the U.S. Department of Education’s Institute of Education Sciences, researchers and curriculum developers at AAAS Project 2061 and BSCS have taken on the challenge of helping middle school students build their knowledge of these essential ideas about chemical reactions and their role in the growth of organisms. In addition to targeting these science content goals, the new unit is also being designed to help students engage in important scientific practices, such as modeling the phenomena they observe and checking to see that the models are consistent with all of their observations. This emphasis on students’ engagement in scientific practices in order to deepen their understanding of core ideas and common themes is consistent with recommendations in the National Research Council’s recently released Framework for K-12 Science Education.

“We want students to be able to use the various models to think through what happens during relatively simple chemical reactions and then use their ideas to explain more complex phenomena in biological systems (such as reactions involving gases which, to many students, seem to simply ‘disappear’),” says Jo Ellen Roseman, who leads the research team and directs Project 2061. Our goal, Roseman added, is to enable students to comprehend science courses in high school and college and to give them a foundation for understanding societal issues such as the ecological impacts of climate change.

The unit develops core ideas and practices into a coherent story for teachers and students,” said Roseman. “The scientific ideas are linked to carefully chosen phenomena and sequenced to make the ideas real to students.”

Learning from Students and Teachers

Development of the new unit is a collaborative process that draws on science learning research and science content expertise (AAAS Project 2061’s team includes a Ph.D.-level chemist and biochemist) along with BSCS’s 50-plus years of experience in developing innovative science curriculum materials, such as its widely used BSCS Biology textbooks. Teachers and students provide another source of valuable input to the process, providing essential feedback on how the new unit is working in the classroom. During pilot testing of the draft unit, the AAAS/BSCS team wanted to gather information on as many aspects of the unit as possible—from which activities seemed to “click” with students, which concepts needed more attention in the unit, and the kinds of supports that other teachers were likely to need in order to use the unit effectively. The pilot test phase also provided the chance to do a “reality check” on more practical aspects of the new unit: Would web-based demonstrations engage students with phenomena they could not observe directly? Could teachers carry out the activities in the time allotted? Would the 3-D molecular models work as expected? Would students be able to follow experiments in which scientists used Carbon-14 labels to follow the fate of carbon atoms from carbon dioxide to glucose to amino acids?

Each day and in each site, members of the team observed the lessons being taught and noted in detail what was working and what needed to be fine-tuned or rethought. The team was also able to interact with students on the spot and in follow-up interviews so that they could get a better sense of which ideas were particularly challenging for students; which activities needed more scaffolding; where additional visualizations, modeling, or discussions questions were needed; and how the lessons could be made more relevant to students’ interests. Many of the activities were captured on video for further analysis later.

To understand how the draft unit worked with a broad range of students, the three pilot test sites in Colorado, Maryland, and Washington, DC, included students of all demographic backgrounds and academic achievement levels. Using a set of multiple-choice assessment items that were carefully aligned to the chemistry and biochemistry ideas targeted in the unit and designed to diagnose whether students held common misconceptions, all of the students were tested before instruction began with the new unit. After instruction, the students were tested again to see if there were learning gains and to see whether misconceptions persisted even after the unit had been taught.

Analysis of the test data is still ongoing, but results so far from classrooms in the District of Columbia and Maryland show that students made statistically significant gains in their performance on the post-test and appeared to hold fewer misconceptions. A closer look at the post-test scores showed that boys and girls made similar learning gains as did students from all ethnic groups and from urban and suburban schools. “These results are very encouraging,” says project director Roseman, “but we have to see if we can get similar results as we move on to more extensive testing of the unit in different classrooms.”

To find out more about the kinds of support teachers are likely to need, pilot test teachers completed a survey before and after they had taught the unit. The survey was designed to explore changes in teachers’ knowledge of the chemistry and biochemistry ideas that are the focus of the unit as well as their knowledge of how their own students were likely to think about those same ideas. “I’m pretty excited about the amount I learned,” one teacher commented.

Teachers were also assessed on their understanding of the curriculum unit itself, the objectives of each activity, and the unit’s goals for student learning. Data from these teacher assessments will provide critical input to the further development of the teacher edition and to the online professional development materials that will support the unit.

Expert Review and Next Steps

Along with teacher and student data from the pilot tests, the AAAS/BSCS team sought input from an external panel of experts who were asked to review both the student and teacher editions of the draft unit. The panel included science teachers and researchers who were experienced in using a curriculum materials analysis procedure developed by Project 2061 for its series of studies evaluating middle and high school science and mathematics textbooks. Working offsite, the panel reviewed the unit and then met with the team to discuss their findings and to suggest revisions. Among other changes, the panel pointed out the need for better framing of each lesson; made suggestions about how best to incorporate video into the lessons; and highlighted a number of issues related to the use of terms such as “food,” “fuel,” and “building materials” that have both common and scientific meanings that could cause confusion for students. The reviewers also recommended changes in the teacher edition to integrate it more closely with the student edition and to offer more guidance on how to help students make sense of their experiences as they use different kinds of models to represent chemical and biochemical reactions.

After examining all of the data, the AAAS/BSCS team met with the pilot test teachers to synthesize feedback on the unit and to consider what changes should be made to the student and teacher editions in preparation for thr next round of pilot testing. The teachers also provided additional insights that will be used to design professional development activities for new teachers who will be involved in the project. A feasibility study is scheduled for 2013.

References

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For more information, contact Dr. Jo Ellen Roseman, 202 326 6752, jroseman@aaas.org.

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