Understanding how ecosystems function is a critical element of environmental education. However, learning about ecosystems can be difficult because of the complexity of the relationships between the different ecosystem components. Past research has shown conceptual representations that enable students to organize these relationships may help them develop the necessary reasoning skills to understand complex systems. These conceptual representations may also allow students to bring these skills to other contexts.
This study was part of an ongoing investigation into the collaborative learning processes and outcomes where classroom-scale aquariums were used to teach ecology. The authors used a conceptual representation model called Structure, Behavior, and Function (SBF) and combined the model with computer-based learning tools to help middle-school students understand the complex biological system inside an aquarium. Specifically, the authors tested the hypothesis that instruction that includes the embedded SBF representation, through guided questions and computer simulation, would lead to more coherent, complex, and expert-like descriptions of the behavioral and functional levels represented in a complex ecological system. The authors provided data from two middle-school classrooms in which students were engaged in a one-week classroom intervention where the SBF framework, alongside computer simulations and worksheets, was used to promote learning about a closed aquarium ecosystem.
The study participants included 138 seventh- and eighth-grade students from two public middle schools in the northeastern United States. The teachers volunteered to pilot the intervention in their science classrooms. The researchers used surveys to conduct pre- and post-test measures to assess knowledge gain and the students' understanding about the complexity of the aquarium systems.
The authors wanted to understand whether the SBF framework could provide the students with language that helped articulate their ideas and whether they could transfer their ideas from one context to another. In the SBF model, structures are the parts of the system; the behaviors are the ways in which the parts operate; and function refers to the outcome or result of the action of the parts. The identification of structures (such as fish, coral, and algae) encourages students to dig into the system and find structures that are not necessarily visible or obvious. Through describing the behavior and function of each structure, students are encouraged to think about how, and to what end, that structure is engaged in systems-level phenomena, establishing a broader frame of reference.
The researchers employed a computer simulation called the RepTools toolkit. This toolkit includes (a) an information source in which images and hyperlinks are embedded into a hypermedia program (the program highlights key structures, behaviors, and function) and (b) two computer simulation modeling tools—one focusing on the macro elements of the aquarium and the other focusing on the micro elements.
The researchers found the students were able to see more than one link between the mechanisms and the parts of the systems, as the intervention (the tools) provided through the program helped to make the mental framework explicit. Students demonstrated significant knowledge gains with regard to structures, behaviors, and functions inside the aquarium after the program; they also had an improved understanding of the complexity of the aquarium system. The overall trend following the intervention was toward higher quality and more coherent explanations of system-level phenomena.
The findings have implications for teaching about complex systems such as ecosystems. When students are encouraged to generate explanations through problem scenarios with specific attention given to underlying mechanisms, they can draw new connections focusing on the functions of ecosystem processes. The use of a conceptual representation such as SBF provides educators with a clear framework for both teaching and assessment.
The complex nature of aquarium systems can enable educators to provide a context for investigating ecosystem ideas, as well as to promote scientific inquiry skills. Because of their size and relatively low cost, aquariums can easily be integrated into classroom instruction. Moreover, because students and teachers are generally familiar with aquariums, they can be model ecosystems for initial interaction. Further, establishing and maintaining an aquarium system provides opportunities for teaching and learning, because it requires an understanding of how biological and physical components within an ecosystem interact. The nature of these interactions also provides an ideal context in which students can apply SBF reasoning.
The Bottom Line
Classroom-scale aquariums can be effective teaching tools for exemplifying complex ecological systems. When partnered with an effective framework—such as the Structure, Behavior, and Function (SBF) model—and coupled with worksheets, computer simulations, and teacher guidance, students can develop deeper, more nuanced critical-thinking skills about complex ecological phenomena. Conceptual representations that enable students to organize the complexity of the relationships among the different parts that comprise an ecosystem—an aquarium ecosystem, in this case—may help students develop the necessary reasoning skills to understand complex systems and to transfer ideas from one context to another.