III Modeling Phases: Generate an Initial Model

The goal of this modeling phase is for the class to generate their first idea of a model for the phenomenon.

This modeling phase does not attempt to get the class to a finished, scientifically accurate model; that is the goal of a later phase. This phase is part of the Level IV: Setting the Stage Mode. After students are presented with a Pattern to be Explained, this phase elicits students' existing ideas about the pattern or phenomenon and also draws out an initial model (or models) that the teacher can help students build on during later modeling phases. In order to elicit student ideas for them to include in their initial models, the teacher may need to ask them repeatedly what explanations they might offer for the pattern or phenomenon. Using Probing Questions can be very helpful here.

Example 1

A unit on circulation in Energy in the Human Body asked students how glucose gets to the cells. After Teacher R introduced the question, she asked the students to move into small groups and whiteboard their ideas. The resulting drawings were the students’ initial models, and the teacher was able to support the students in building on these models in the succeeding lessons.

This drawing of a human figure has a throat and stomach with green particles inside, intestines, red arteries leading from a heart to the intestines and then to a capillary in the hand. The green dots are duplicated in a key outside the figure, labelled with the words "Glucose" and the chemical formula for glucose.The figure is an initial model generated by one of the small groups. This group explained that the woman eats an apple, which goes to the intestines. The glucose from the apple then gets absorbed into an artery.

This and other initial models were built upon in succeeding lessons as the students and teacher together constructed a model of intestinal structure that offered a deeper explanation of how glucose is absorbed into the blood.

Using this whiteboard method to collect and share initial student drawings and explanations is an effective way to initiate imagistic thinking and detect the current state of student thinking about their scientific models.

Initial Model 2: The same cartoon drawing of a head as in the previous image, but annotated differently. This one has separate tubes from the nose and the mouth extending down through the neck and not joining together. These initial models were evaluated later during a Model Competition Mode. Initial Model 1: Cartoon drawing of a human head, annotated with a single tube from nose and mouth going down the neck. Particles show that food is in that tube.Example 2

In another lesson, the teacher’s target was to get students to understand the structure of the throat, including the windpipe and the epiglottis. She began by asking students, “What is the structure of the throat?” and had them draw their initial models.

In Examples 1 and 2, Teacher R facilitated the Model Generation phase by Asking Students to Provide Model Elements. While gathering student’s ideas, she avoided evaluating them or asking for evaluations; this process was reserved for a later phase.

This is not the only method for supporting initial model generation; Teacher N sometimes takes a whimsical approach.

Example 3

T: What is your model of what happens in your stomach when you eat? My own model is that food goes down and hits a blade that churns around and chops it up…

Teacher N uses this example to show students that explanatory models don’t have to be exact representations, but should offer some explanation of how things work. He reports success getting students to generate a variety of initial models this way, which then gives the class something to work from in the next modeling phases, Model Evaluation and Model Modification.

The next example also engages students in a playful way.

Example 4

Teacher N uses this invitation to support students in generating an initial model for structures inside the human body, "Imagine you lived 400 years ago before anyone knew how the inside of the body looked…" 


Supporting and Contributing Strategies

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

II. Creative Reasoning Processes to Support Generation

Suggestions for managing a type of discussion that can be very useful here are included under:

I. Participation Strategies

Strategies under Visualization Strategies that may be helpful can be found here:

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.

Some of the background for this phase and how it fits into the larger framework is in 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 is found in 

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

More in-depth discussion of eliciting students' existing ideas to generate initial models is found in 

Generating, evaluating, and modifying scientific models (Price & Clement, 2014)