SEP6: Constructing Explanations and Designing Solutions

from NGSS Appendix F: Science and Engineering Practices in the NGSS

The goal of science is to construct explanations for the causes of phenomena. Students are expected to construct their own explanations, as well as apply standard explanations they learn about from their teachers or reading. The Framework states the following about explanation: 

“The goal of science is the construction of theories that provide explanatory accounts of the world. A theory becomes accepted when it has multiple lines of empirical evidence and greater explanatory power of phenomena than previous theories.”(NRC Framework, 2012, p. 52) 

An explanation includes a claim that relates how a variable or variables relate to another variable or a set of variables. A claim is often made in response to a question and in the process of answering the question, scientists often design investigations to generate data.  

The goal of engineering is to solve problems. Designing solutions to problems is a systematic process that involves defining the problem, then generating, testing, and improving solutions. This practice is described in the Framework as follows. 

Asking students to demonstrate their own understanding of the implications of a scientific idea by developing their own explanations of phenomena, whether based on observations they have made or models they have developed, engages them in an essential part of the process by which conceptual change can occur.  

In engineering, the goal is a design rather than an explanation. The process of developing a design is iterative and systematic, as is the process of developing an explanation or a theory in science. Engineers’ activities, however, have elements that are distinct from those of scientists. These elements include specifying constraints and criteria for desired qualities of the solution, developing a design plan, producing and testing models or prototypes, selecting among alternative design features to optimize the achievement of design criteria, and refining design ideas based on the performance of a prototype or simulation. (NRC Framework, 2012, p. 68-69) 

from A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (page 52)

The goal of science is the construction of theories that can provide explanatory accounts of features of the world. A theory becomes accepted when it has been shown to be superior to other explanations in the breadth of phenomena it accounts for and in its explanatory coherence and parsimony. Scientific explanations are explicit applications of theory to a specific situation or phenomenon, perhaps with the intermediary of a theory-based model for the system under study. The goal for students is to construct logically coherent explanations of phenomena that incorporate their current understanding of science, or a model that represents it, and are consistent with the available evidence.

Engineering design, a systematic process for solving engineering problems, is based on scientific knowledge and models of the material world. Each proposed solution results from a process of balancing competing criteria of desired functions, technological feasibility, cost, safety, esthetics, and compliance with legal requirements. There is usually no single best solution but rather a range of solutions. Which one is the optimal choice depends on the criteria used for making evaluations.

from NGSS Appendix F: Science and Engineering Practices in the NGSS

The end-products of science are explanations and the end-products of engineering are solutions. 

The goal of science is the construction of theories that provide explanatory accounts of the world. A theory becomes accepted when it has multiple lines of empirical evidence and greater explanatory power of phenomena than previous theories. 

The goal of engineering design is to find a systematic solution to problems that is based on scientific knowledge and models of the material world. Each proposed solution results from a process of balancing competing criteria of desired functions, technical feasibility, cost, safety, aesthetics, and compliance with legal requirements. The optimal choice depends on how well the proposed solutions meet criteria and constraints.

K-2	3-5	MS	HS
Constructing explanations and designing solutions in K–2 builds on prior experiences and progresses to the use of evidence and ideas in constructing evidence-based accounts of natural phenomena and designing solutions.	Constructing explanations and designing solutions in 3–5 builds on K–2 experiences and progresses to the use of evidence in constructing explanations that specify variables that describe and predict phenomena and in designing multiple solutions to design problems.	Constructing explanations and designing solutions in 6–8 builds on K–5 experiences and progresses to include constructing explanations and designing solutions supported by multiple sources of evidence consistent with scientific ideas, principles, and theories.	Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.
Use information from observations (firsthand and from media) to construct an evidence-based account for natural phenomena.	Construct an explanation of observed relationships (e.g., the distribution of plants in the back yard).	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.
	Use evidence (e.g., measurements, observations, patterns) to construct or support an explanation or design a solution to a problem.	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 they did in the past and will continue to do so in the future.  Apply scientific ideas, principles, and/or evidence to construct, revise and/or use an explanation for real-world phenomena, examples, or events.	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.  Apply scientific ideas, principles, and/or evidence to provide an explanation of phenomena and solve design problems, taking into account possible unanticipated effects.
	Identify the evidence that supports particular points in an explanation.	Apply scientific reasoning to show why the data or evidence is adequate for the explanation or conclusion.	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.
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.	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.	Apply scientific ideas or principles to design, construct, and/or test a design of an object, tool, process or system.  Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.  Optimize performance of a design by prioritizing criteria, making tradeoffs, testing, revising, and re-testing.	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.

Goals for SEP6: Constructing Explanations and Designing Solutions

from A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (page 69)

By grade 12, students should be able to 

• Construct their own explanations of phenomena using their knowledge of accepted scientific theory and linking it to models and evidence. 
• Use primary or secondary scientific evidence and models to support or refute an explanatory account of a phenomenon. 
• Offer causal explanations appropriate to their level of scientific knowledge. 
• Identify gaps or weaknesses in explanatory accounts (their own or those of others). 

In their experience of engineering, students should have the opportunity to 

• Solve design problems by appropriately applying their scientific knowledge. 
• Undertake design projects, engaging in all steps of the design cycle and producing a plan that meets specific design criteria. 
• Construct a device or implement a design solution. 
• Evaluate and critique competing design solutions based on jointly developed and agreed-on design criteria.

K-2	3-5	6-8	9-12
K-PS3-2 1-PS4-2 1-PS4-4 1-LS1-1 1-LS3-1 2-PS1-3 2-ESS1-1 2-ESS2-1	3-LS3-2 3-LS4-2 4-PS3-1 4-PS3-4 4-PS4-3 4-ESS1-1 4-ESS3-2 3-5-ETS1-2	MS-PS1-6 MS-PS2-1 MS-PS3-3 MS-LS1-5 MS-LS1-6 MS-LS2-2 MS-LS4-2 MS-LS4-4 MS-ESS1-4 MS-ESS2-2 MS-ESS3-1 MS-ESS3-3	HS-PS1-2 HS-PS1-5 HS-PS1-6 HS-PS2-3 HS-PS3-3 HS-LS1-1 HS-LS1-6 HS-LS2-3 HS-LS2-7 HS-LS4-2 HS-LS4-4 HS-ESS1-2 HS-ESS1-6 HS-ESS3-1 HS-ESS3-4 HS-EST1-2 HS-ETS1-3

A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (pages 67-71)

Science Practices Continuum - Students' Performance
This tool is a continuum for each practice that shows how students' performance can progress over time. A teacher can use the continuum to assess students' abilities to engage in the practices and to inform future instruction. From Instructional Leadership for Science Practices.

Science Practices Continuum - Supervision
This tool is a continuum for each practice that shows how instruction can progress over time. An instructional supervisor can use the continuum to identify the current level for a practice in a science lesson. Then the supervisor can provide feedback, such as offering instructional strategies to help move future instruction farther along the continuum. From Instructional Leadership for Science Practices.

Potential Instructional Strategies for Constructing Explanations and Designing Solutions
This instructional strategies document provide examples of strategies that teachers can use to support the science practice. Supervisors might share these strategies with teachers as they work on improving instruction of the science practices. Teachers might find these helpful for lesson planning and implementing science practices in their classrooms. From Instructional Leadership for Science Practices.

Bozemanscience Video