the practice of modeling

Modeling has been identified as a science practice that is useful for refining explanations about how something happens in the world. In science classrooms, models typically include a combination of pictorial representations and written explanations about 'seen' and 'unseen' mechanisms that describe how and why a particular phenomenon occurs.   

When we use scientific modeling in the classroom, we enact a cycle of constructing, revising, and testing our models against the real world. Models play a central role in an MBI unit in that they link the real with the abstract, or the phenomenon with the important science ideas we use to explain it. The diagram below shows this relationship.  

We do not think of models as the product of a unit. Instead they are a tool by which groups of students are able to make sense of ideas around a phenomenon. The practice of modeling makes students' thinking visible (to themselves, their peers, and to you), allows groups of students to work through ideas as they negotiate the model, and helps generate new ideas and hypotheses to be tested. As represented in the diagram to the right (taken from Helping Students Make Sense of the World Using Next Generation Science and Engineering Practices, p. 115), models are not merely depictions of phenomena. Instead, models are tools for students to make sense of phenomena.




Example student models

Here is a great resource on models and modeling in science classrooms from the Ambitious Science Teaching group. The primer contrasts how models are used in science with how they are traditionally used in science classrooms before providing practical advice for integrating modeling in science classrooms. Pay special attention to the 'Helpful advice from teachers' section at the end!

What should be included in student models?

It's also important to give students options in terms of the explanatory elements they can choose from as they construct their models. Arrows showing connections, zoom in windows showing what is happening on a molecular level, or explanatory text boxes are important elements of student models.

Using Templates to scaffold student modeling

Choosing whether or not to provide students with a template for their models is an important decision. In some instances, a blank piece of paper provides students with more agency over how they choose to represent their ideas. In others, students will get further by being provided a template that provides a much-needed structure for their ideas. These are decisions based on the age of your students, their familiarity with modeling, and other factors.

We recommend reading A Layered Approach to Scientific Models by Fowler, Windschitl, and Auning (2020) for a comprehensive exploration of model templates. Click on the image to the right to be taken to this great resource. Their article is rich with example templates including:

To these we add partitioned templates, which are similar to before, during, and after templates but focus more specifically on change over short time periods.

Using a Partitioned Template is one way to support students by amplifying the focus on changes in the complex anchoring phenomenon over time. This is important since, in most cases, it is the changes that happen overtime that are most important to explain, because these involve unseen mechanisms that provide explanatory power both in the unit anchoring phenomenon and in related phenomena.

The example highlighted here comes from:

Campbell, T. & Neilson, D. (2016). Explaining ramps with models: Design strategies and a unit for engaging students in developing and using models. The Science Teacher. 83(5), 33-39. (available to NSTA members)

Constructing initial models

After students have been introduced to the anchoring phenomenon and have worked together to create their initial hypotheses to answer the driving question, it is time to construct their initial models. At this point, we like to emphasize that deciding as a group what will go on the model and how is important intellectual work and that they will be revising their models throughout the unit. Models are tools to help them make sense of the science ideas as they build their explanation of the phenomenon. It's also worth pointing out that this stage of the unit is about eliciting their own ideas, before you as the teacher have introduced any science ideas. While it's sometimes difficult not to introduce important ideas about the phenomenon, it's important to hold off until the next stage where you will be able to introduce new ideas to reason with through the tasks you have chosen for the unit. At this point, it's ok (and very fruitful!) if the groups' models are incorrect or are missing important information. 

We recommend the following procedure for constructing initial models:

At this point, many of the groups' models will be simple representations of what happened, but will lack the causal mechanism, or the 'why' things happened. That's ok and perhaps something to point out after the share-out session.

An example initial model of a middle school plate tectonics unit.

Revising Models

Now that they have revised their thinking through a number of purposeful tasks, it’s time to revise their initial models. This step is important not only to help drive their thinking, but as a formative assessment to see the progress the groups have made in coordinating the science ideas toward a cohesive scientific explanation of the phenomenon.

We recommend the following procedure:

An example revised model of a middle school plate tectonics unit.

Finalizing models

As we move into the building consensus stage, we utilize models as a sensemaking tool one more time. In this case, our goal is to use the construction of the groups' final models to finalize revisions based on the last few purposeful tasks and to bring the groups to consensus on a final evidence-based explanation of the phenomenon. 

We recommend the following procedure:

An example final model of a middle school plate tectonics unit.

Putting it all together

Much of this information can be found in the NSTA commentary Using Models to Teach Science by our colleagues Byung-Yeol Park, Laura Rodriguez, and Todd Campbell. They use the following four questions to guide our use of models in teaching science: