III Modeling Phases: Identify the Pattern to be Explained

The goal of this modeling phase is to identify the focus of the lesson: something that needs an explanation that can be provided by a model.

This modeling phase (Level III) supports the teacher and students in Setting the Stage (Level IV). Before students generate their initial model, they need to have some idea of what it is that their model will try to explain. What is the question the model will answer or the kind of prediction we hope it will make? There are a number of activities a teacher can use, depending on the phenomenon and the type of model. For instance, a teacher can show a video that presents some puzzling phenomenon (such as the popular oil tanker implosion video), or do an interactive demo that yields unexpected results (asking students to predict the effect beforehand), or lead a discussion that raises the issue and begins to focus on the important aspects of the issue (“We are interested here in why the tanker imploded, not in why the tanker had no oil in it”). Often a teacher will use a combination of methods. The objective is not to specify what the initial model will be, but to help students become focused on the issue at hand much the way a scientist might. How does blood circulate? How is it we can both breathe and eat through our mouth, but not at the same time? In the air syringes you just experimented with, why could you not push the plunger all the way in? Why did the 10th light bulb in the circuit you just constructed light up as brightly as the 1st bulb, which was right next to the battery?

In each of these examples, the initial activity prepares students to move to the next modeling phase, Generating an Initial Model. Two more complete examples follow.

Example 1

In an inquiry into the overall structure of the human circulatory system (Energy in the Human Body), a teacher wanted students to generate a model of how oxygen gets to the cells in the body. They had already learned about oxygen in the lungs and about blood delivering oxygen to the cells, but they did not have a model of how all this worked together. The teacher drew a diagram on the board that represented what the students already knew, with a gap representing what they still needed to figure out. The pattern to be explained was how all of the cells in the body get fresh oxygen-rich blood all of the time. A discussion that clarified this helped prepare the students for their next task, which was to move into small groups and Generate an Initial Model for connecting the lungs into the circulatory system.  

This diagram was used to show the gap, for which students would generate a model to explain. Lungs are shown in one part of the picture. Entirely separate from the lungs is a circulatory loop that connects a heart and a capillary bed elsewhere in the body. The question for the students is how the lungs might be connected to the heart and circulatory system.

Example 2

A whimsical cartoon model of a human head shows a nose and mouth, but no detail at the back of the nose or mouth or in the neck. There is a question mark outside the mouth. The question mark represents the unknown pattern that the students will need to explain, the internal structure of the throat.In a different lesson, about the structure of the throat, a teacher had middle school students reason about the throat structure that allowed them to use their mouths to both breathe and eat. This was the pattern to be explained. The discussion prepared the class for the next modeling phase, the Model Generation phase. In this highly productive lesson, students themselves generated models of a throat structure that branched into two tubes, one to the lungs and one to the stomach, and also had something that would make food go into the correct tube (Model Evaluation and Modification Example 4).


Supporting and Contributing Strategies

Reasoning processes and strategies that support this phase of the modeling sequence are found in:

II. Creative Reasoning Processes to Support Identifying a Pattern to be Explained

There are many Visualization strategies that may be helpful. Among them:

I. Imagery Talk
I. Depictive Gestures
I. Scientific Drawings



A discussion of this modeling phase in the context of a classroom example is in Core of this Approach.

For how this phase fits into the larger framework, see the Level III section of the Educator's Tour.

For more discussion on the theoretical underpinnings of the framework, see the Introduction to the Full Theory page.


Articles, Papers and Websites

More in-depth discussion of this modeling phase, along with a slightly earlier iteration of the framework, is found in the following paper by our team:

Large scale scientific modeling practices (Nunez-Oviedo & Clement, 2019)