UMassAmherst | College of Education

Developing Models in the Classroom

Discussion-Leading Strategies to Support the Scientific Practice of Modeling

Part 2: For Teacher Educators Who Have at Least 3 to 5 Classes to Devote

(2-3 additional lessons to follow Part 1)
 

Leading Modeling Discussions

In this section teachers will learn about leading modeling discussions in which they first draw out and then scaffold the evolution of student models toward the target model. It is recommended to engage with the prerequisite activities and resources here:

A. Learn to lead Idea-Eliciting Discussions using Participation Strategies

before doing Part 2. In Part 2 we will:

Introduce Modeling Instruction and its Advantages
B. Learn to select a targeted Model (‘Big Idea’)
C. Learn to select a Pattern to be Explained
D. Learn About Generating Initial Models via Model Eliciting Discussions
E. Learn about leading Guided Model Construction Discussions: Scaffolding the Evolution of  Student Models Toward the Target Model.

Items B and C can be thought of as prerequisites for learning to lead modeling discussions.  This site concentrates most on the modeling strategies for items D and E and other strategies presented in Part 3.

Introduction to Modeling Instruction and its Advantages

From here on we will simply use the term ‘teachers’ to refer to ‘teachers or teacher candidates following this course of study’. 

Teachers can read the Krajcik & Merritt (2012) article “Engaging Students in Scientific Practices: What does constructing and revising models look like in the science classroom?” which provides a concrete example of a modeling lesson. This lesson is at the upper elementary level but the principles involved can be applied to all grade levels.

Questions to consider, write about, and discuss after reading the article:

  1. When using the term Models, what are the authors referring to?
  2. What are some forms in which models can exist?
  3. What are some aspects of models that are important for students to understand?
  4. What is the traditional use of models in science classrooms?
  5. What middle school example do the authors provide for engaging students in the modeling processes of constructing and revising models based on evidence?
  6. Why are the students asked to develop models for the travel of odors at three different times during their exploration of the particle nature of gases?
  7. How is this process different than the traditional strategy of providing students with the scientific model of particle behavior?

Discuss the advantages of modeling as a science teaching approach, which include:

  • The teacher is gaining diagnostic feedback on student thinking, and therefore insights into the many conceptual pieces that need to be learned or unlearned. Both teacher and students contribute ideas and evaluations of ideas.
  • Even though 30-50% of the ideas will come from the teacher or readings, there is still a very active reasoning role for the students in Guided Discussion.
  • There is the resulting potential for many students to become engaged in scientific reasoning.
  • Students share and listen to each other’s ideas to build a community of learning.

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B. Learn to Select a Targeted Model For a Lesson Or Unit (selecting a ‘Big idea’)

‘Teaching with models’ is different from ‘teaching topics’ in science.  Unlike science teaching that focuses on presenting ‘finished’ correct models to students, model-based science instruction engages students in constructing models that provide underlying explanations for observations that they encounter. We will refer to these as ‘explanatory models’ or simply ‘models’.   

At this point teachers can read the paper Primer – Planning for engagement with important science ideas from the Tools for Ambitious Science Teaching website at the U. of Washington. They refer to explanatory models as ‘Big Ideas’.   This is because explanatory models function as the conceptual glue for a unit of study; the central important concepts that everything relates back to. They offer examples of central models as ‘Big ideas’ from a range of grade levels and areas of scientific study. 

C. Learn to Select a Pattern to be Explained

We also make the important distinction between hidden underlying explanatory models as opposed to visible or known observations that may come from teacher demonstrations, discrepant events, video clips, photographs, or news articles about particular scientific phenomena. Some teachers will need practice in distinguishing empirical Observation Patterns from theoretical, explanatory Models used to explain them.

When we find a particularly motivating event that can provide visible or known observations as the starting point for a lesson, the AST site refers to it as an Anchoring Event. These can be used as hooks or springboards to cause students to ask themselves, “Why did that happen?” making them ready to construct a model that explains why the event happened.  In a sense, the anchoring events or observed phenomena can serve as the ‘what’ and the explanations or models that students construct are the ‘why’.

A good way for teachers to strengthen and confirm their understanding of the differences between models and anchoring events is to complete the Collaborative Tool–Planning for Engagement on the AST website for a science topic of their choice.

Drawing out Prior Knowledge

In areas where students have practical background knowledge about a phenomenon but need help with scientific vocabulary used to describe those observations, a brief discussion of their experiences can be a good starting point.

So far we are assuming that a modeling unit begins from the starting point of a set of Observations (using an anchoring event if we can find one) before one proceeds to construct a model explaining those observations.  However there is also another possible starting point. This is to:

  • Select a Model that is already known to the students and ask them to extend the model to a deeper Level (e.g. “We already know that we get glucose needed for energy from digestion, but how does glucose get from the intestine into the bloodstream?). We call this a request to Deepen an Explanation.

We refer to these two kinds of starting points for a unit collectively as examples of a Pattern to be Explained. At this point teachers can read through the Setting the Stage for Modeling in Guided Inquiry, Identify the Pattern to be Explained, and Supports for Identifying a Pattern to be Explained strategies in the Strategy Catalog section of this website.

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D. Learn About Generating Initial Models via Model Eliciting Discussions

After students have comprehended a Pattern to be Explained, which might take the form of an anchoring event, the next phase of the modeling process is to engage students in a Model Eliciting Discussionin which they brainstorm to generate candidate models providing explanations. Usually these begin with the teacher asking students to ‘explain why the X (pattern to be explained) occurred.’

Teachers being educated via this syllabus by now have already learned about general strategies for leading Idea Eliciting Discussions using the Participation Strategies on the site. They can now apply these same strategies to a Model Eliciting Discussion. However, an important additional strategy is pressing for explanations because some students will simply add more detailed observations of the phenomenon rather than contributing pieces of an underlying model or mechanism to explain why the phenomenon occurred.

It is crucial at this stage that the teacher remain non-judgmental and allow all ideas to be taken into consideration by the students, since later we will want students to participate in evaluating the merits of all models proposed.

The next steps are:

Introduction to the Air in the Tire Transcript

This is an Eliciting Discussion for drawing out students’ models.

In this clip from a 7th grade class that is halfway into a unit on properties of gases, the teacher has had one of the students pump air into a bike tire.  The students have had lessons on gas particle models, and he is trying to get students’ to reason about pressure in a gas and the fact that the pressure rapidly self-equalizes everywhere in an enclosed chamber.  He does this by posing a question about whether pressure is higher near the valve of a bike tire than in other parts of the tire as air is pumped in. This is a ‘thick’, high cognitive load question because it is not just about what they have observed. It asks students to reason about a hidden model, the elastic particle model, and to give explanations.

Key Points

The teacher first takes a hand vote on this question to get students invested in the issue. Note that he then explicitly draws out opinions on both sides of the question. He does this for an extended period of time without revealing his own position, recognizing that reasonable arguments can be given on both sides of this question. Because this is a Model Eliciting Discussion, his goal is to draw out their different ideas, not to converge on a right answer.  (That will come later in  Model Evaluation Discussion.) He attempts to set up an atmosphere in class where each student’s opinion is valued. He paraphrases students’ remarks to help the rest of the class understand them, but he stays completely neutral for the moment about whether they are correct. This kind of preparation should help to get students to ‘own the question’ of how gas particles behave inside of a chamber. Teachers need to practice the skills of staying neutral and listening carefully to understand (and if necessary clarify) student ideas while encouraging as many students as possible to contribute.

Introduction to the Yeast Experiment Videos

Days 4, 5, 6 Yeast Experiment Round 1, a video from the AST site, provides examples of the teacher pressing for model-based explanations that go beyond the observations students made in a lab. (Focus on minutes 0 to 5:25 at least.)

The video illustrates how students are accustomed to labs being only about recording observations, and the need to press students to go beyond that if they are to do modeling and explanation. The website introduces the teacher’s objective:

  • Fungi were used as examples to show how these life processes are characteristic of all living things. She chose to focus on the role of fungi in decomposing matter, how they digest matter, how they use cellular respiration to generate energy from sugars and why they use this energy–which is chiefly used for reproduction. In this way the unit shifted from being about yeast as a topic with some focus on yeast processes to being about an explanation for why yeast decompose matter.
  • Students worked to develop the following model, which includes the processes of extra-cellular digestion, absorption, and cellular respiration: Complex carbohydrates + enzymes > sugar and oxygen > energy + carbon dioxide
  • To focus the students on the idea that yeast exemplify processes of all living things and to generate student interest, the teacher used the essential question, “How am I similar/different than a fungi?” to frame the unit.
  • Students mixed yeast, carbohydrates, sugar and water in flasks closed with a balloon on top.

In the follow up video Day 9 & 10 Generating evidenced-based explanations, one can also see the teacher pressing for explanations after students do their first comparison experiment. They manipulated amounts of sugar, carbohydrates, temperature and other variables in an experiment of their own design. (Focus on minutes 5:24 to 8:30 or 12:50 at least.)

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E. Learn About Leading Discussions for Improving the Model (Evaluating and Modifying Models)

Since students can generate diverse models that are only partially correct or that are sometimes in conflict with the targeted scientific model, the third essential component or phase of the modeling process is to guide them in the Evaluation and probable Modification or improvement of their explanatory models. Whereas model generation can be done in brainstorming discussions without much cognitive scaffolding, for model improvement discussions, more strategic scaffolding on the part of the teacher is often desirable. This makes it more challenging for the teacher but it is very important since it engages students in the type of processes that scientists undertake as they assess, debate, argue, support, and refute various ideas and theories on their way to reaching mutually agreeable explanations. The difference between these two types of discussion, as well as an example from a middle school life sciences unit, can be reviewed in the Core of This Teaching Approach page of this website.

In order to learn about Leading Discussions for Improving the Model, the following activities are suggested.

Introduction to the Circuits Transcript

Figure shows a series circuit in the form of a rectangle with a bulb at the top capacitor on the right side, and another bulb at the bottom.


Figure 1.  Circuit A: 2 Bulbs and Capacitor

Figure 2 is the same figure as the previous one, except there is also a battery on the left-hand side of the rectangular Siri Circuit.


Figure 2.  Circuit B: 2 Bulbs, Battery, and Capacitor

This transcript comes from a high school class using the CASTLE electricity curriculum where the surprising effects of capacitors are being considered. Not all teachers will be versed in the behavior of capacitors discussed in this transcript; nevertheless, the ciruit behavior is described there and pre-service teachers have reported being able to understand the teaching strategies being used in the segment.

After making observations in lab, students in whole class discussion agree that the lights did not come on in Circuit A, Fig. 1, when the bulbs were connected to a discharged capacitor. In building series Circuit B, students noticed that when connected, the bulbs would light for about 3 seconds (as the capacitor charged) and then fade out. The teacher first simply asks them whether they agree on their observations from the lab (transcript lines 1-8). But then he begins to ask them to generate a model to explain what happened by saying, “What do you think that means? What happened in the Circuit B?” This is the beginning of model elicitation, which is then followed by model evaluation and improvement.

Questions to Consider and Discuss After Analyzing This and Other Transcripts or Videos

  1. How is what these teachers are doing different from a “traditional” teaching approach?
  2. In what sense are the teachers or supporting students to Generate Initial Models? Evaluate Models? Modify Models?
  3. How are these Model Construction Strategies that the teachers are using different from the general Participation Strategies they use?
  4. For teacher statement X from transcript Y, what else could a teacher say here that might work?

Alternatively, teachers can read an excerpt from the paper by Williams and Clement (2015) that includes diagrams of the student-teacher interactions and involves no capacitors. However the discussion strategies terminology used is older. The paper discusses three strategy levels:

  • Participation Strategies (referred to in the paper as Dialogical Strategies)
  • Modeling Phases (referred to as Macro Strategies)
  • Creative Reasoning Strategies (referred to as Micro Strategies)

Teachers can read the Abstract; then starting on page 90 with the paragraph ‘The purpose of this qualitative study….’, they can read through page 95.

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Improving the Model in Small group Discussion

Not all model construction work that students do should happen within the whole class discussion format. Small group and Individual assignments will foster participation by all students. Read a short piece on Building a Modeling Classroom Culture for Small Group Work that explores the importance of mixing small group and whole class activities in model-based teaching. Although this site concentrates on whole class discussion leading strategies, it is assumed that a teacher education course will cover small group techniques for developing small group norms and skills using other resources such as Kagan & Kagan’s (2009) Cooperative Learning: Frequent Questions. For example, modeling teachers will often start the model generation process by having small groups draw models on a small white board or poster paper, then have some of the models discussed by the whole class. Individual work such as drawing one’s own labeled version of a model and comparing it with others and revising is also crucial for comprehension.

There is a lot of variation in how much scaffolding teachers do during model evolution. If partial models need to be evaluated and modified, one teacher may use a sequence of very frequent or less frequent leading questions to support this in whole class discussion. Another teacher may assign the task to small groups if he/she believes that the students are ready to engage that challenge. Teacher judgment is required.

This Rolling Carts Video, from the AST website, shows an example of an experiment done in small groups designed to help 5th and 6th grade students generate , evaluate, and modify their early models of inertia. They are trying to figure out why two different sized clay balls (“passengers”) in a cart rolling down a hill and crashing into a brick wall move differently when they are thrown from the cart in the crash. They are trying to figure out how to reconcile their complex observations with their initially simple restatement of a definition of inertia.

Here the experiment helps foster model generation through predictions, but the teacher then uses a lot of scaffolding to help the small groups evaluate and modify their models starting from the surprising observations they make but also working from Newtonian ideas that they have started to learn. Notes can be entered on this Rolling Carts Rough Transcript Outline.

In this Gallery Walk to Critique Models video from the AST website, a 5th grade teacher instructs students in how small groups can critique each other’s models constructively in a gallery walk through posters displaying their models.

Visualization Strategies

Visualization strategies appear at Level 1 in our framework and provide support for all the other levels of cognitive strategies by engaging imagery and imagistic reasoning processes in the brain that are essential to modeling.

Introduction: Imagery Support Charades

Have teachers play a pictionary game, where the teacher writes a phrase describing a dynamic scene. Each small group of teachers are given a phrase describing some object doing an action (i.e. parachute jumping from a plane).

They then have to act it out for others to guess the phrase. In the first round they can use no words, but could use drawings and gestures. Second round they can use only gestures. Discuss the differences in these experiences. Then discuss the analogy between the value of drawings for communicating images of events in this exercise and their value in learning dynamic models in science.

Another option is to precede these activities by having teacher groups create a concept map of the importance of imagery in Science Education, then discuss in whole class.

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Activities to Introduce Teachers to Visualization Strategies

  • Introduce the difference between internal mental imagery that happens entirely in the head and external diagrams, drawings and pictures that are referred to by some as ‘images’ in everyday language. Here we use the terms ‘image’ and ‘imagery’ to refer to internal mental imagery.
  • Ask teachers to imagine two rooms in a house they have lived in and to describe the number of windows in each of two of the rooms, as an example of internal imagery.
  • Read this preprint of an NSTA journal paper on the role of imagery in science learning by N. Price, et al. (2017). Class discussion questions are provided for the article.
  • Read the Visualization Section of the Strategy Catalog for more examples of Visualization strategies.
  • Students can complete a Matching Exercise for Visualization Strategies. A Key for this exercise is also available.
  • The  Transcript for the Leg Veins Video can be used again here to practice identifying Visualization Strategies. (In the docx version of the transcript file, add a column or replace a column heading with the heading ‘Visualization Strategies.’) Teachers can work from the list of strategies in the Key for Visualization Strategies. Our interpretive analysis of the transcript is available in the Leg Veins Key to Strategies at Four Levels.  Visualization strategies are tracked in the column with that label.   

Big Picture Perspective

Teachers who want to gain a big picture perspective on Strategies to Support Modeling can do so by reading about and discussing figures 1 and 4 on the Full Theory page of this site at this point.

How Students and Teachers Can Keep Track of Modeling Ideas in Writing and in Drawings

An interesting guide for this important topic is the Guide to Face to Face Tools for representing ideas externally, available from the Ambitious Science Teaching website.

Other Resources

Many other resources are also available on the Ambitious Science Teaching site from the U. of Washington, including many extended video examples. The tools there are especially valuable for teachers who wish to give even greater responsibility to students for evaluating and revising models over extended time periods, in order to further develop their thinking skills.

Other sites:
Model Based Biology 
American Modeling Teachers Association (AMTA)

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NEXT ->   Part 3: Additional Discussion-Leading Strategies

Downloads:

Air in the Tire Transcript.pdf  and .docx
Building a Modeling Classroom Culture for Small Group Work.pdf
Circuit Video Transcript.pdf and .docx
Key – Generation Strategies.pdf and .docx
Key – Evaluation and Modification Strategies.pdf and .docx
Key – Participation Strategies.pdf and .docx
Key – Visualization Strategies.pdf and .docx
Leg Veins Transcript Exercise.pdf and .docx
Leg Veins Key to Strategies at 4 Levels.pdf and .docx
Match Exercise – Generation Strategies.pdf and .docx
Match Exercise – Model Evaluation and Modification.pdf and .docx
Match Exercise – Participation Strategies.pdf and .docx
Match Exercise – Visualization Strategies.pdf and .docx
Role of Imagery in Science Learning.pdf
Role of Imagery in Science Learning – Discussion Questions.docx
Rolling Carts Rough Transcript Outline.pdf and .docx