The Framework for K–12 Science Education (National Research Council [NRC] 2012) and the Next Generation Science Standards (NGSS Lead States 2013) have shifted conceptions of science teaching and learning in several ways. One of the most important shifts is using phenomena to frame instruction. Students’ primary task during instruction is to develop scientific explanations about a phenomenon and make predictions about related phenomena. Phenomenon-based instruction differs from previous science education paradigms where students’ primary task involves learning about various science topics.

A second shift is the emphasis on integration of science and engineering practices (SEPs) with disciplinary core ideas (DCIs) and crosscutting concepts (CCCs). In explaining phenomena, students engage in the SEPs in support of learning DCIs and CCCs and then use the three dimensions together to demonstrate their learning. These NGSS shifts have had profound implications for the planning, implementation, and assessment of science learning.

Modeling and phenomenon-based instruction

Modeling as a practice is particularly well suited to phenomenon-based instruction and is an important SEP described in the NGSS. Modeling is so important to learning science in the NGSS era that several groups developing curriculum materials for the NGSS explicitly ground their units in modeling, including A Medical Mystery (BSCS Science Learning 2019), MBER Biology, NextGenStorylines, and OpenSciEd (see links to websites in Online Resources).

There are different conceptions about modeling (Gouvea and Passmore 2017; NRC 2012). Gouvea and Passmore (2017) contrasted “models of” something (in which students do 1:1 mapping between the real object and the model) with “models for” explaining or predicting something that happens in the world.

Because “models for” implies that students are actively engaged in high-level cognitive activity, we call this modeling. Students’ cognitive processes and mental imagery behind their explanations and predictions are referred to as a conceptual model. By contrast, a visual or physical representation, what Gouvea and Passmore (2017) described as “models of,” can help teachers convey science ideas. Students examine these representations to help them understand what may be difficult to visualize related to the science content they are learning. We call these content representations (models of) to contrast with the more cognitively active process of modeling (models for). If you would like to learn more about modeling, we recommend papers by Wingert and colleagues (2019) and Fowler, Windschitl, and Auning (2020).

Why is coordinating modeling with content representations important?

As students develop their understanding of complex scientific processes, it is important that they have the opportunity to use content representations as they develop explanations or make predictions through modeling. In fact, several simple content representations may be combined in a meaningful way (i.e., coordinated) as students develop models to explain and predict more complex phenomena.

For example, consider a common activity in which dialysis tubing filled with starch solution is immersed in an iodine solution. Students can watch the starch solution slowly turn dark blue as iodine molecules pass through the tubing and interact with the starch. The starch–iodine content representation of a cell is a useful way to visualize that cell membranes regulate the movement of matter in and out of a cell, but understanding this function of membranes is only one part of explaining a larger phenomenon—absorption of nutrient molecules from inside the small intestine for transport to the body. Students who are engaged in modeling what happens to food during digestion could reference the starch–iodine content representation to help them explain absorption, but explaining the entire process requires more than this one piece of the puzzle. Students need to coordinate the starch–iodine content representation with other content representations in order to develop and use a conceptual model to explain and predict digestion.

Coordinating modeling activities with content representations can lead to deep understanding for students, but it isn’t easy. Helping students succeed in putting multiple pieces together requires that the teacher carefully plan the sequence of instruction, implement instruction meaningfully so that students can make sense of content representations and refine their models multiple times, and assess students’ understanding along the way. Table 1 summarizes these facets.

To illustrate how planning, implementation, and assessment come together to support students in modeling to explain complex phenomena, we draw on examples from the freely available digital unit—A Medical Mystery (the complete student and teacher editions are available at the link in the BSCS Science Learning reference).

Planning

Engaging students in modeling to explain phenomena and make predictions requires extensive planning. To ensure that the science storyline is coherent from the students’ perspective, teachers must carefully select and sequence learning experiences that allow students to iteratively create and revise conceptual models that gradually increase in explanatory power.

Planning to engage students in modeling requires teachers to create and use their own conceptual model to explain the phenomenon. Teachers’ models should reflect an ideal student response. Teachers then contrast this ideal model with what they anticipate students’ initial models might include, which allows teachers to plan for the learning trajectory.

The conceptual model that explains the phenomenon will draw on multiple science ideas. By listing these science ideas, which are typically closely aligned to the DCIs targeted for instruction, teachers can define the science content space for the phenomenon.

Sequencing science ideas so that the storyline will be coherent from the student perspective requires considering questions students might initially ask about the phenomenon and how those could evolve during the unit. The unit phenomenon and the questions that arise for students as they observe and wonder about the phenomenon are key determinants of how the unit will unfold. Anticipating student questions is necessary for planning the sequence of ideas to be figured out and, in turn, the sequence of learning activities.

With the set of science ideas and their sequence established, a teacher can consider which activities and content representations are likely to support students in answering their questions and determining new ones to pursue. Also important are (1) the question of how frequently students should revise their models and (2) deciding what not to teach. Distracting details can interfere with students’ development of a concise and coherent conceptual model with broad explanatory or predictive power.

To focus students’ sensemaking work, a clear purpose should be agreed on by the class. This happens through planning the coordinated use of several pedagogical strategies (Roth et al. 2011):

• Set a purpose with a focus question or lesson question. This strategy helps students see what they hope to figure out in the lesson. The focus question is especially effective if it derives from students’ curiosity about the phenomenon or emerges from a gap in understanding in their initial conceptual models. Answering the focus question helps fill in the missing pieces to their explanations.
• Plan for how to help students link science activities to science ideas. Plan to support students in making links between activities and science ideas and ask students to articulate these links to help them remain focused on how the activity furthers their understanding about the anchor phenomenon.
• Plan for how to help students link science ideas to other science ideas. Each supporting science idea students learn will help them explain more aspects of a phenomenon. Plan for when students will link a content representation and an idea from one lesson to a new content representation and a new idea learned in another lesson. As students connect ideas, they build their conceptual models to explain phenomena and make predictions about related phenomena.
• Plan to highlight key science ideas and the focus question throughout a lesson. Intentionally identifying points in the lesson where you plan to highlight key science ideas will help students stay focused on key science ideas. By highlighting key ideas throughout a lesson, the teacher reminds students of their collective purpose.

Implementation

Careful sequencing of learning experiences helps students make sense of the storyline, but students may find content representations embedded in learning experiences too visually complex to reconcile with the systems they represent. Students will need support for making sense of individual content representations, making connections across multiple representations, and creating a coherent conceptual model that integrates multiple content representations to explain phenomena. Teachers can support students in the following ways: (1) simplifying visually complex content representations to distill their important science ideas, (2) helping students identify and interpret key aspects of the content representation, and (3) focusing instruction on coordinating multiple content representations to explain parts of a phenomenon.

To support students in making sense of complex content representations, scaffolds could include a tool for identifying and interpreting key elements in a representation and an explanation tool that uses evidence from content representations to support a claim:

• An identification and interpretation tool directs students to identify what they see in the content representation and interpret what it means (matching each “What I see” statement to one “What it means” statement). If a complex content representation includes multiple elements, students can use their “What I see” and “What it means” statements to write a caption describing the content representation and distilling its important ideas.
• An explanation tool guides students in making a claim and supporting it with evidence and reasoning. On the tool there is space for them to state the claim, list relevant evidence, and share reasoning for why the evidence supports the claim.

See Supplemental Materials at the end of this article for the teacher edition and the student edition for both the identify and interpret tool and the explanation tool.

Assessment

It is critical to assess students as they coordinate the use of content representations in service of modeling. Teachers interpret what students are saying, writing, and drawing and use that information to make instructional decisions.

Assessment proceeds in stages, with multiple formative assessment opportunities before summative ones. Students share their initial models with peers and get feedback from the teacher or the class. They identify questions that emerge from initial attempts to model the phenomenon. As they engage in additional learning opportunities, they iteratively refine their models to reflect their evolving understanding. Assessment of models should reflect the stage of instruction, with the expectation that students won’t have all the right answers at the outset (A Medical Mystery includes comprehensive formative and summative assessments with suggestion for how teachers might implement them).

In assessing students, the teacher should monitor (1) students’ uptake of science ideas from each content representation and (2) how students incorporate those ideas into their developing conceptual models. A series of sketches accompanied by text descriptions rich with action words would allow teachers to determine whether students are integrating the ideas from various content representations into their models. The power of using modeling to explain phenomena resides in pushing students to go beyond drawing pictures with one-word labels (typical of content representations). Imagery from the various content representations would likely appear in students’ drawings, but students’ model-based explanations would reveal much about their developing understanding of the target phenomenon.

Based on what students draw, write, and say, the teacher would consider whether students have mastered the learning goals and whether reteaching might be necessary.

Conclusion

Coordinating modeling with content representations can strongly support students’ three-dimensional learning. Carefully planning the sequence of instruction allows teachers to integrate appropriate content representations in service of students’ iterative model-building work. Successful implementation includes the use of scaffolds to ensure that students can make sense of content representations. Formative assessment allows teachers to consider students’ model-based explanations of DCIs and CCCs, revealing students’ challenges and providing important clues for reteaching.

Online Resources

MBER Biology—www.modelbasedbiology.com/front-page

NextGenStorylines—www.nextgenstorylines.org

OpenSciEd—https://www.openscied.org

Supplemental Materials

Teacher edition identify and interpret tool—https://bit.ly/3DwPBWq

Student edition identify and interpret tool—https://bit.ly/3DyN2n4

Teacher edition explanation tool—https://bit.ly/3DxXvyW

Student edition explanation tool—https://bit.ly/3sxUh8p

Susan M. Kowalski (susan.kowalski@nwea.org) is a senior manager of the learning sciences R&D group at NWEA in Portland, Oregon. Betty Stennett is a science educator and Lindsey Mohan is a senior science educator and associate director for program innovation, both at BSCS Science Learning in Colorado Springs, Colorado.