There are so many misconceptions about the Science and Engineering Practice of Developing and Using Models. When I first started shifting my focus to the Next Generation Science Standards, I didn't know what modeling should look like in an NGSS aligned classroom. Below, I give you the answers to some of my early questions about models.

## What is the Science and Engineering Practice of Developing and Using Models for the NGSS?

It is important that we define modeling through the lens of the NGSS. A model is a dynamic representation of a student's current understanding of an event, system, or process. I say that they are dynamic because they chage over time as students begin to understand more about the content.

Models are tools for sense-making. They should be used to improve student understanding over time and expose misconceptions. They are not just tools used to evaluate students.

It is also important that students are responsible for creating the model. Teachers should not be providing students with step-by-step instructions for creating the model. Instead, teachers can provdie guidelines that help students understand what their models should included.

#### Models are developed over time.

Ideally, students develop their model over the course of a lesson sequence instead of a single lesson. So, they will revist their model several times over the course a lesson sequence. Each time, their model will be revised. Gradually, student models will become more detailed and accurate.

##### It's okay if an initial model has flaws.

Students will have misconceptions and misunderstandings when they are introduced to a new concept. Usually, I have students create a simple drawing at the start of a lesson sequence. I do not provide students with any guidelines.

Then, after students have obtained more information, we will come up with a list of components that should be represented in the model. Often, we use the Crosscutting Concept of Systems and System Models to help us with this task.

As a class, we decide what makes a good model and come up with some general criteria as a class.

#### The Way I Used Models Before NGSS

Earlier this week, I posted this picture on my Instagram of what models used to look like in my classroom. This was in 2013-ish, when everything I knew about the standards came from a pdf copy of the standards that I'd found somewhere. Like Jon Snow, I knew nothing.

Many of you might still be having your students create models that look just like this in your classroom and you might be wondering what is wrong with this type of model. Please know, I am not model-shaming you. Learning how to meet the intent of these standards is truly a process.

Let me briefly explain what is wrong with the models in this picture. Students created these models at the END of my instructional sequence. These models show what students understood about cells after I provided them with the information. In this case, students were not using the models as a sense-making tool. Students weren't using modeling as a sense-making tool.

##### Students should be developing the models themselves.

Often, I see educators providing students with a models that they are being asked to recreate. For example, of often see teachers using the Oreo Cookie Moon Model.

In this model, teachers provide students with the phases of the moon. Then, students recreate this model using Oreo cookies.

If presented in this way, this would not meet the intent of modeling according to the NGSS. Students are neither developing nor using the model. Instead, they are replicating a model that was created for them.

## What types of models can students develop or use?

The NGSS refers to several different types of models that should be used in your science classroom. These include:

- Diagrams
- Simulations
- Replicas
- Equations
- Physical Models

The students do not always need to be developing their own model. The students can use a model that is provided for them in order to improve their understanding of a phenomenon.

For example, students can use simulations to increase their understanding of content. I find that simulations are especially helpful when the scale or other factors prevents us from doing investigations in the classroom.

Also, physical models are great tools to improve student understanding. For example, using a water table is a great tool. Students can use this tool to see how changes in elevation can affect the landforms that are created by flowing water.

### More Information About Developing and Using Models for NGSS

- Crosscutting Concepts: Systems and System Models for NGSS
- Digital Models for NGSS
- Teaching Science in 3D Podcast: Developing and Using Models for NGSS
- Four Ways to Help Improve Student Models

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