SEPs: Constructing Explanations and Designing Solutions

Science and Engineering Practices: Constructing Explanations and Designing Solutions

This practice involves constructing explanations of phenomena and designing solutions to engineering problems. To be accepted within the scientific community, scientific theories must be supported by research and evidence. Without the support of peer-reviewed evidence, a scientific theory or explanation is just a guess—even if that theory happened to be correct, it could not be validated as so.

Frequently, theories undergo years and years of research and are developed upon many times before an explanation is widely accepted. For example, scientists have been compiling evidence for the big bang theory since the early 1900s—when it was first proposed, it was considered quite radical.

Conversely, a scientific theory that was once accepted can be disproven by a new theory as evidence comes to light—known as a superseded theory.

In engineering, the goal is to design effective solutions to engineering problems. Usually, there are a multitude of solutions to a problem, and engineers seek the one that best satisfies a range of criteria, including desired functions, safety, cost, or aesthetics¹.

Constructing Explanations and Designing Solutions: Progression

Primary School (K–2)

1. Use information from observations (firsthand and from media) to construct an evidence-based account for natural phenomena.
2. Use tools and/or materials to design and/or build a device that solves a specific problem or a solution to a specific problem. Generate and/or compare multiple solutions to a problem.

Elementary School (3–5)

1. Construct an explanation of observed relationships (e.g., the distribution of plants in the backyard).
2. Use evidence (e.g., measurements, observations, patterns) to construct or support an explanation or design a solution to a problem. Identify the evidence that supports particular points in and explanation.
2. Apply scientific ideas to solve design problems.
Generate and compare multiple solutions to a problem based on how well they meet the criteria and constraints of the design solution

Middle School (6–8)

1. Construct an explanation that includes qualitative or quantitative relationships between variables that predict(s) and/or describe(s) phenomena. Construct an explanation using models or representations.
2. Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students’ own experiments) and the assumption that theories and laws that describe the natural world operate today as it did in the past and will continue to do so in the future.
3. Apply scientific ideas, principles, and/or evidence to construct, revise and/or use an explanation for real-world phenomena, examples, or events.
4. Apply scientific reasoning to show why the data or evidence is adequate for the explanation or conclusion.
5. Apply scientific ideas or principles to design, construct, and/or test a design of an object, tool, process or system.
6. Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.

7. Optimize the performance of a design by prioritizing criteria, making tradeoffs, testing, revising, and re-testing.

High School (9–12)

1. Make a quantitative and/or qualitative claim regarding the relationship between dependent and independent variables.
2. Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.
3. Apply scientific ideas, principles, and/or evidence to provide an explanation of phenomena and solve design problems, taking into account possible unanticipated effects.
4. Apply scientific reasoning, theory, and/or models to link evidence to the claims to assess the extent to which the reasoning and data support the explanation or conclusion.
5. Design, evaluate, and/or refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.

Grades K–2 Progression

In K–2, students learn that scientists and engineers construct explanations and design solutions. They begin to attempt to create their own explanations based on observations, using descriptive language to explain phenomena. If you are investigating what plants need to grow, your students should first come up with hypotheses—guesses as to what they think will happen—and then as the experiment progresses they will start to build up evidence that plants need sunlight and water to grow.

Grades 3–8 Progression

As students progress into upper elementary, they should start to identify specific pieces of evidence that support their explanations and construct explanations that specify variables.

Engineering challenges are a great way for students to start designing solutions. For elementary-age students, one of the most popular—and fun—is a classic egg drop experiment, where students design a container to protect a raw egg when dropped onto the ground from a predetermined height. The students can go through the process of designing their containers and deciding what materials they will use. They might carry out their drop and then make changes to their design to better support their egg. You could even hold a competition to compare multiple solutions and evaluate why some eggs survived and why others didn’t. These challenges can get more complex as the students get older and start to include variables and specific criteria to help them determine which solution is best suited.

By middle school, students start to plan and undertake complex investigations to produce explanations, supported by evidence, and start to include models or representations—including drawings and diagrams, or physical replicas—to help them explain phenomena. Their explanations should be supported by multiple sources of evidence, and they should be able to verify the validity of these sources. They can also start to read scientific texts and make claims using evidence from within the text—this will also help get them used to more intricate scientific terminology.

Learn More About Constructing Explanations and Designing Solutions with Twig Science

Download our free printable Constructing Explanations and Designing Solutions poster to serve as a reminder for your students that this practice is an important part of the process of scientific investigations.

To ensure that you hit the three dimensions of science learning, you need the support of a comprehensive 3-D science program. Twig Science is a phenomena-based science program that ensures all students have an interwoven understanding of Crosscutting Concepts, Science and Engineering Practices, and Disciplinary Core Ideas.