New Curriculum Outperforms Traditional Biology Materials

Middle school biology students exposed to new curriculum that makes connections between the physical and life sciences have a better grounding in chemistry once in high school. | Jo Ellen Roseman/AAAS

Students using a new middle school curriculum unit developed by Project 2061, AAAS’s long-term science education initiative, had a better understanding of chemistry concepts central to modern biology than students using traditional curriculum materials, according to a newly published study.

Students who used Project 2061’s Toward High School Biology unit also held far fewer misconceptions about atom rearrangement and conservation during chemical reactions than students in a comparison group, according to the study, published in the December 2016 issue of CBE-Life Sciences Education, an online peer-reviewed journal of the American Society for Cell Biology.

“A great deal of research shows that misconceptions about chemistry are often the root cause of difficulties in understanding basic biological processes such as plant and animal growth and the role of plants in removing carbon dioxide from the air,” said Jo Ellen Roseman, principal investigator for the study. One reason for this, explained Roseman, is that traditional textbooks rarely take advantage of opportunities to help students make connections across physical and life science. “It was clear to us that concepts from life science and physical science needed to be much better integrated,” she added.  

The Toward High School Biology unit includes eight weeks of learning activities in which students make sense of real-world phenomena involving chemical change, from the rusting of a bicycle left out in the rain to the growth of a small puppy into an adult dog. Throughout the unit, which is designed to support recommendations in the Next Generation Science Standards, which set forth goals for K-12 science education content, students make observations, collect and analyze data, use molecular models to make sense of the production of new substances in terms of the rearrangement and conservation of atoms during chemical reactions and develop explanations of related phenomena using relevant evidence and scientific principles.

At each step, the unit helps students understand how the same principles can be used to explain phenomena across a variety of physical and living systems. Chapters 1 and 2 help students develop an understanding of chemical reactions by focusing on simple, nonliving systems where the production of new substances can be directly observed. In Chapters 3 and 4, the central concepts developed in the first two chapters are applied to the more complex context of growth and repair in living organisms, where the link between starting and ending substances isn’t transparent.

The new study reports on results from a final field test in which six teachers and nearly 600 students participated in a small-scale randomized control trial. The trial compared outcomes of three groups of students whose teachers were either using the Toward High School Biology unit for the first time (novice users); using the unit for the second time (experienced users); or using the business-as-usual school district curriculum that targeted the same science ideas as the Toward High School Biology unit.

An analysis of students’ pre- and post-test scores showed a significant positive correlation between use of the Toward High School Biology unit and higher post-test scores, with the students whose teachers were experienced users of the unit showing the largest effect size.

Project 2061’s new curriculum unit was also more successful than the business-as-usual curriculum in reducing the prevalence of commonly held student misconceptions, researchers reported. “We used known misconceptions as possible answer choices in our pre- and post-test questions so that we could track changes in students’ thinking,” said Cari Herrmann-Abell, a AAAS researcher and lead author on the newly released paper. An item-by-item analysis of the results showed which misconceptions students started with and whether they still held those misconceptions after instruction. For the misconception that cell division alone accounts for growth in living organisms, for example, Herrmann-Abell noted that 26% of students using the district curriculum still held that misconception after instruction, but only 7% of the students using the Toward High School Biology unit did.

More than 25 teachers and 4,000 students in Colorado, the District of Columbia, Maryland, and Massachusetts have been involved in the five-year development of the Project 2061 curriculum unit. Teachers provided feedback directly from the classroom to help improve the unit through several cycles of pilot testing and surveys. “I am thrilled with where [the unit] is at this point, and I will use the unit again because I enjoy teaching it and my students enjoy it as well,” reported one veteran teacher. “I feel that the students benefit from the [new biology curriculum] THSB and that our students who participate feel better prepared for what to expect in high school,” said another.

The AAAS team partnered in the unit’s development with science educators and curriculum developers at Biological Sciences Curriculum Study a curriculum research and development organization in Colorado known as BSCS. The work was supported by a grant from the Institute for Education Sciences at the Department of Education.