“…While one would generally expect them to understand less about the more complex forms, the existing research reveals developing competencies across the levels of the dimensions. These forms support the building of systemic understanding in science and increasingly there is a call to revise curriculum to build such understanding (e.g., Mayer & Kumano, 1999). The most recent research does indicate a greater interest in investigating complex causal concepts (e.g., Friedman, 2001;Metz, 1998a;Wilensky & Resnick, 1999).…”