# 8 - The Ross Periodic Table is a Pedagogical Model!

### Scientists use specialized models to do scientists' work.

## Teachers need pedagogical models to do teachers' work.

Science teachers' pedagogical models must meet a very demanding set of requirements. Any pedagogical model should have the following features.### 1. Easy To Learn

A pedagogical model should require little student effort to learn to great accuracy of student representation. A pedagogical model must contain within itself the smallest possible set of structural errors, to avoid the student having to "unlearn" inadequate ideas in the future.

The Ross periodic table is quickly memorized, easily interpreted, and is useful for years of post-secondary education.

### 2. Accommodates a wide spectrum of students in a given class

A pedagogical model should match the needs of students who differ in ability, age, previous achievement and future learning.

*With only three salient features, the Ross model enables students of different ability to make progress.*

### 3. Advances every student's capacity to explore

No matter their position on the spectrum, all students are driven to explore. A pedagogical model should support the student as she asks her own questions and undertakes the labs that investigate chemical behavior.

**The simple Ross representation of atomic structure enables students to make predictions, and test them experimentally.**

### 4. Is Scientifically Tenable

At the very least, a pedagogical model of the atom should have fewer errors than alternative models. Furthermore, a pedagogical model of the periodic table should *support* students as they increase their knowledge of more sophisticated models.

A pedagogical model should match the largest possible set of explanations of more advanced theories. At the same time, a good pedagogical model should not contradict the more advanced models, except at its very extremities, and it must certainly not contradict more advanced models at its core. For learners, it must support the students who go on to learn more advanced models, without having to be "unlearned."

**The Ross model has fewer errors and omissions than the Bohr-Rutherford and Lewis models.**

** Because it coheres with quantum descriptions of atomic structure, the Ross model supports advanced learners. **

### 5. Advances Students' Understanding Of Science

The epistemology of science is not easy to convey to novices. Research in science teaching shows that naïve pedagogical approaches to the "methods of science" distort the scientific enterprise. Typically, the Baconian model of science alienates many students from the study of science, because the Baconian model does not correspond to the ways that students actually explore the world.

A pedagogical model must invite students to participate in real scientific investigation, and reward them with honest findings.

**The Ross model supports students as they test and refine their own representations of atoms**

### 6. Invites Students To Create New Knowledge

The scientific enterprise is about creating and verifying new knowledge. How can we initiate students into this epistemic activity? Research in science education has clearly showed that "memorizing dead science" has not been very effective for learning how science is really done. We know that "discovery science" has not worked any better. The IntuitivScience approach may be more effective.

IntuitivScience focuses upon the student's own representations. When teachers help their students to learn to use simple and fruitful models, then students can work at creating models that correspond to the world of their own experience. When students are responsible for their own representations, they work harder to refine them.

#### Teachers need pedagogical models to do teachers' work.

The Ross model of the atom and the Ross periodic table are pedagogical models. Students who internalize these models are better able to represent and interpret their own new knowledge of chemical behavior.