Next Generation Science Standards (NGSS) Overview

NGSS Background

Traditionally, science has been perceived by most as an elite subject and occupation. There has been a growing movement to provide greater access to STEAM education and thereby promote diversity within STEM fields. There is also a growing understanding that regardless of their career choices, students need to develop scientific literacy in order to make informed personal choices and be involved, responsible citizens.

It was against this backdrop of urgency that the Next Generation Science Standards were developed. A group of eighteen people with science and education backgrounds, including two Nobel laureates, were convened by the National Academy of Sciences and began the task of writing a framework for what science education could look like in the United States. They sought to include research-based, successful pedagogy, to incorporate science content and skills relevant in the 21st century, and to build a comprehensive plan that provided all students with access to a complete science education. The result was A Framework for K-12 Science Education, released in 2011. NGSS was developed based on the framework, and the standards were published in 2013 with each state given the option of adopting them. To date, 20 states and the District of Columbia (D.C.) have adopted NGSS, and 20 other states are using similar standards that were developed based on the framework.

The core of NGSS is learning that empowers students and puts them in the role of investigators and designers. This was a move away from traditional science standards—lists of facts and concepts students should know by the end of a school year. With traditional standards, many students perceived science as something static and sterile, something to be learned rather than done. The framework called for a move towards learning that is student-centered, where they consistently engage in scientific inquiry. Additionally, in order to address pertinent topics such as climate change and requirements for STEM careers that often involve interdisciplinary work, the framework called for the inclusion of earth and space science (not previously a required discipline) and engineering in the core content.

three-part NGSS loop Logo with the words, practices, core ideas and crosscutting

Dimensions of NGSS

NGSS consists of three dimensions that are woven together. The first dimension is Science and Engineering Practices (SEPs). There are eight practices which are intended to give students experiences engaging in the same work as scientists and engineers.

The second dimension is Cross Cutting Concepts (CCCs). These are major themes that are seen in all of the science domains. Students learn to identify and describe the seven CCCs as they study various topics throughout their science education and develop an understanding of the integrated nature of science.

The third dimension in NGSS is the domain-specific content taught, Disciplinary Core Ideas (DCIs). Between two and four core ideas are identified for each domain—physical science, life science, earth and space science, and engineering, technology and application of science. Each core idea has sub-ideas (“component ideas”) that are introduced and elaborated on in a spiral method through the grade levels.

At each grade level, and by subject area for middle school and high school, there are specific Performance Expectations (PEs). Rather than a list of what students should know, these performance expectations focus on what students can do based on their experience with the NGSS dimensions and include language from all three dimensions woven together.

As the performance expectations suggest, the overall aim of NGSS instruction is that students experience three-dimensional learning, they use elements of all three dimensions to understand a phenomena or problem and develop an explanation or solution. It is not always possible for all three dimensions to be equally represented in an activity or lesson, though in some cases this happens. However, the three dimensions should have roughly equal representation and be integrated together as often as possible in units and over the course of a school year.

How to Read the Standards

To better understand NGSS, see the article, How to Read the Next Generation Science Standards. For the purposes of the INTEGRATE alignment documents, the codes are as follows:

Science and Engineering Practices (SEPs)

SEP 1: Asking questions and defining problems.
SEP 2: Developing and using models
SEP 3: Planning and carrying out investigations
SEP 4: Analyzing and interpreting data
SEP 5: Using mathematics and computational thinking
SEP 6: Constructing explanations and designing solutions
SEP 7: Engaging in argument from evidence
SEP 8: Obtaining, evaluating, and communicating information

Crosscutting Concepts (CCCs)

CCC 1: Patterns
CCC 2: Cause and Effect
CCC 3: Scale, proportion, and quantity
CCC 4: Systems and system models
CCC 5: Energy and matter
CCC 6: Structure and function
CCC 7: Stability and change

Disciplinary Core Ideas (DCIs)

The core ideas are coded based on discipline:

ESS: Earth and Space Science
ETS: Engineering, Technology, and Applications of Science
LS: Life Science
PS: Physical Science

When a DCI is referenced, the number and letter following the code indicate which core idea and supporting component idea for that discipline are being referred to.


  • LS1.A refers to Life Science Core Idea 1 (From Molecules to Organisms: Structures and Processes), Component A (Structure and Function)
  • LS1.B refers to Life Science Core Idea 1 (From Molecules to Organisms: Structures and Processes), Component B (Growth and Development of Organisms)

To view a chart listing all core and component ideas for each discipline, view the document on the national website: How to Read the Next Generation Science Standards.

Performance Expectations (PEs)

PEs have a code that indicates the grade level, DCI, and the order of performance expectations for this grade.

Example: HS-LS1-1
HS: High School (grade level)
LS1: Life Science DCI 1 (discipline and core idea)
1: The number of the performance expectation for this grade level related to that specific DCI (in this example, this is the first of seven for this DCI. The final one is coded HS-LS1-7).

Additional NGSS Components

In addition to the three dimensions, there are other important components of NGSS instruction and three dimensional learning. The ones that are highlighted in the INTEGRATE alignment charts are explained below:

Use of Phenomenon and Problems

Within NGSS, phenomena are described as occurrences in the natural or human-made world that can be observed and cause one to wonder or ask questions. It’s recommended that authentic phenomena and problems be used as the basis of lessons and units. Students are introduced to an interesting, relevant example and over the course of activities and lessons are asked to bring together the knowledge and skills they are developing to explain a phenomenon or develop a solution to a problem.

The Nature of Science

Appendix H of the NGSS outlines the importance of teaching students about the nature of science and that it is a human process. Multiple strategies are recommended within this appendix. They include incorporating examples of historic scientists and scientific study as well as providing opportunities to learn about current scientists and their work. Students should be provided with examples of how science changes with new discovery and invention and should be able to reflect on and discuss the potential and limitations of the scientific process.

Inclusion of Engineering

As previously stated, a major shift in NGSS is the inclusion of engineering in the content of science courses. NGSS calls for engineering design and scientific inquiry to be taught simultaneously. Engineering is defined as developing solutions to real world problems. In addition to learning the foundations of engineering design, students should be provided with examples and experiences that help them understand the relationships between science, technology, society, and the environment (Appendix J).

Developing Literacy Skills

The development of literacy skills and science understanding can be integrated. Appendix M of NGSS outlines how closely reading texts, making inferences, and developing arguments supported by evidence can be an opportunity to simultaneously deepen literacy and science understanding.