What Are the Features of a "Pedagogical Model?"

Very simply, any pedagogical model applied to learning science should:

• Be easy to learn. It should require the least possible student effort, provide the greatest possible accuracy of student reproduction, and ensure the smallest possible set of structural student errors.
  
• Accommodate a wide variety of students. The ability, age, previous achievement and future learning of high school students spans a spectrum as wide as humanity itself. A pedagogical model should be within the intellectual grasp of most students within this spectrum. It should also enable those students to make progress, no matter where they begin on the spectrum.
  
• Be scientifically tenable. At the very least, it should have fewer errors than the B-R and Lewis models. It should match the largest possible set of explanations and predictions of more advanced theories. It should contradict more advanced models only at the very extremities of its application, and certainly not at its core.
  
• Advance every student’s capacity to explore. No matter where they begin on the spectrum, all students are driven to explore by their innate curiosity. A pedagogical model of the atom should enable students to explore their own questions about chemical behaviour.
  
• Advance students’ understanding of science. The epistemology of science is not easy to convey to novices. Naïve approaches to “methods of science” distort the scientific enterprise, and alienate many students from the study of science. A pedagogical model would invite students to participate in scientific investigation, and reward them with honest findings.
  
• Invite students to create knowledge. The scientific enterprise is about creating and verifying new knowledge. How can we initiate students into this epistemic activity? Memorizing dead science has not worked. “Discovery” science has not worked. A pedagogical model of the atom would support students as they create and express their own new knowledge of chemical behaviour.

Scientists use models to do scientists' work. Teachers need models to do teachers' work.