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Complex Systems
SBF Theory
Research Questions
Proposed Studies

Complex Systems
Life science is often about understanding complex systems- from human body systems to ecosystems to evolution. These are notoriously difficult to understand because it requires understanding how structures relate to functions and what the behaviors of the system are. Understanding a system involves considering the causal interactions and functional relationships among the parts of the system. Some interactions between parts are invisible and have a time sequence that makes them difficult to perceive. Even adults struggle to learn about complex systems (Feltovich et al., 1992). Yet such understanding is often critical to scientific analysis. The behaviors of the individual elements interact in such a way that the overall function of the system emerges from the behaviors of the components. These difficulties may be aggravated by the static depictions found in typical textbooks that focus on structures without considering the dynamic behaviors and function. It is not surprising then that learners often focus exclusively on perceptually apparent structures. This oversimplification of complex phenomenon that can cause enduring misconceptions (Feltovich et al., 1992).
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SBF Theory

One possible approach to teaching about complex systems involves the use of a conceptual representation drawn from Structure-Behavior-Function (SBF) theory (Goel & Chandrasekaran 1989). According to this theory, systems consist of multiple related levels—the structures, or parts, or the system, the functions, what the system actually produces, and the behaviors, which are the mechanisms by which the structures produce their functions. We need to understand more about what it means to understand a complex system and that understanding complex systems can be enhanced with appropriate conceptual tools, such as the SBF representation, and representational tools that provide opportunities to foreground function and make invisible, dynamic behaviors available for direct observation.

Example SBF Questions for Teachers

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Research Questions

This proposal outlines a series of studies that will address three major research questions:
1) What does it mean to understand a complex system?
2) How can providing an explicit conceptual representation support learning about complex systems?
3) How can dynamic representational tools support learning about this conceptual representation?
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Proposed Studies

In the first of four studies, I will investigate what children know about complex systems and identify learning trajectories by comparing middle school children with novice adults and experts. This will provide a developmental analysis that runs from children with little experience learning about biological systems to adults who will have at least completed high school science and may have taken a college course or two in science, and experts. The SBF model will be used as a framework to analyze people’s thinking. The experts should understand a great deal about functional and behavioral aspects of the system but the novice adults may know more about structures than the middle school children but it is not that they would have a better understanding of functions and behaviors.

Study 2
The second study will examine using SBF as an explicit conceptual tool that can be used to structure a hypermedia learning environment that will use the SBF framework to move middle school students from their prior knowledge identified in Study 1 to a more sophisticated functional understanding. While providing an explicit representation can enhance students understanding of function, the hypermedia will be essentially a static representation of SBF. To gain a deep understanding of the behavior of complex systems, learners need a way to make their mental models of complex systems visible, test them out, repair their misunderstandings, and reevaluate their models. A static representation does not make dynamic behaviors salient nor does it allow learners to test out their conceptions. I suggest that by providing students with an appropriate representational tool, the Virtual Construction Kit (VCK), a simulation model construction kit, they will be able to make their thinking visible and get the dynamic feedback necessary for them to construct deep understanding, particularly of system behaviors.

Study 3
Study 3 will test this idea in a middle school classroom environment as students use the VCK to support design and modeling activities. Allowing students to make their thinking visible and providing dynamic feedback should support deepening understanding to the extent that students are able to interpret the results of their simulation but it is possible that some learners may need help in interpreting what they see (to prevent them from inventing new misconceptions). The SBF hypermedia from Study 2 may serve as a useful tool to help in interpretation and guide students' discovery
Study 4
Study 4 will examine how using multiple representational tools jointly contribute to student learning about complex systems. This builds on Study 3 by investigating how the explicit SBF model from the hypermedia can scaffold student’s design and modeling activities.

This material is based upon work supported by the National Science
under Grant No. 0133533. Any opinions, findings and
conclusions or recomendations expressed in this material are those of
the author(s) and do not necessarily reflect the views of the National
Science Foundation
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Last updated February 23, 2010