Science

The 8 NGSS Science and Engineering Practices, Explained for K–5

By Pluma Team · October 22, 2026

TL;DR

The eight NGSS Science and Engineering Practices (SEPs) are what scientists and engineers do: ask questions and define problems; develop and use models; plan and carry out investigations; analyze and interpret data; use math and computational thinking; construct explanations and design solutions; argue from evidence; and obtain, evaluate and communicate information. In K–5 they look simple (observing, drawing, comparing, explaining with evidence), but students should use them in nearly every science lesson.

In this article you will find

Why the practices matter
The eight practices at a glance
1. Asking questions and defining problems
2. Developing and using models
3. Planning and carrying out investigations
4. Analyzing and interpreting data
5. Using mathematics and computational thinking
6. Constructing explanations and designing solutions
7. Engaging in argument from evidence
8. Obtaining, evaluating and communicating information
Making room for the practices in a short science block
How the practices work in a unit
Supporting all learners

The eight NGSS Science and Engineering Practices are the things scientists and engineers actually do (ask questions and define problems, develop and use models, plan and carry out investigations, analyze and interpret data, use math and computational thinking, construct explanations and design solutions, argue from evidence, and obtain, evaluate and communicate information), and in K–5 they turn science from reading about facts into doing science. They’re one of the three dimensions of the Next Generation Science Standards, together with the Disciplinary Core Ideas (the content) and the Crosscutting Concepts (the big connecting ideas). This guide explains each practice in plain language, shows what it looks like in K–2 and 3–5, and gives you sentence stems and quick activities. For the full structure of the standards, see our NGSS science standards guide.

Why the practices matter

Before the NGSS, many elementary science lessons followed a familiar pattern: read about a topic, watch a demonstration, fill in a worksheet. The practices shift the focus to students figuring things out. Instead of being told that plants need light, students ask what plants need, plan a test, collect observations, notice patterns and explain their results with evidence.

The practices are written as “practices” rather than “skills” on purpose. A skill can be practiced in isolation; a practice is used to make sense of something real. A lesson that teaches students to read a thermometer is a skill lesson. A lesson where students use thermometers to find out which spot in the schoolyard is warmest at noon, and then explain why, uses several practices.

The eight practices at a glance

#	Practice	K–2 looks like	3–5 looks like
1	Asking questions and defining problems	Asking questions from observations; describing a simple problem	Asking testable questions; defining a problem with criteria and constraints
2	Developing and using models	Drawings, diagrams, physical replicas	Models showing relationships or how something works
3	Planning and carrying out investigations	Simple tests with guidance; observing and measuring	Planning fair tests with variables controlled
4	Analyzing and interpreting data	Recording and sharing observations; simple charts	Tables, bar graphs; looking for patterns
5	Using math and computational thinking	Counting, comparing quantities	Measuring, calculating, graphing
6	Constructing explanations and designing solutions	Explaining with observations; building a simple solution	Explanations with evidence; comparing multiple solutions
7	Engaging in argument from evidence	Sharing ideas and listening to others	Supporting claims with evidence and reasoning
8	Obtaining, evaluating and communicating information	Reading or listening to texts; sharing findings	Combining information from texts and data; presenting

1. Asking questions and defining problems

Scientists ask questions about the natural world; engineers define problems to solve. In K–2, students ask questions based on observations: “Why does the ice melt faster on the sidewalk?” In 3–5, they learn to ask questions that can be tested and to define a design problem with criteria (what the solution must do) and constraints (limits like materials or time).

Stem: “I wonder what would happen if…” / “Our problem is… A good solution must…”

Quick activity: Show a short, puzzling phenomenon (a can that crushes itself, seeds that sprout faster in one cup) and have students write as many questions as they can in three minutes. Sort them into “we could test this” and “we’d need to research this.”

2. Developing and using models

A model is a representation that helps explain or predict. In K–2, models are drawings, diagrams and physical replicas, like a drawing of where a bird gets food and shelter. In 3–5, models show relationships and processes that can’t be seen directly, such as the path of water through the water cycle or how sound travels as vibrations.

Stem: “My model shows… The arrows mean…” / “One thing my model doesn’t show is…”

Quick activity: Before and after a unit, students draw a model of the same phenomenon. Comparing the two drawings is a powerful way to show learning.

3. Planning and carrying out investigations

In K–2, students conduct investigations with guidance: testing which materials keep an ice cube frozen longest, or observing how a plant changes over two weeks. In 3–5, they plan fair tests themselves, deciding what to change, what to measure and what to keep the same.

Stem: “We will change… We will measure… We will keep the same…”

Quick activity: Give groups the same question (Which ramp height makes a toy car go farthest?) and let each plan a test. Then compare plans and discuss what makes a test fair.

4. Analyzing and interpreting data

Data only becomes evidence when students look for patterns. K–2 students record observations with pictures and tallies and compare them. 3–5 students organize data into tables and bar graphs and describe patterns, such as “the higher the ramp, the farther the car went.”

Stem: “I notice that… The pattern is… This surprised me because…”

5. Using mathematics and computational thinking

In science, math is a tool. Younger students count, compare and use simple measurement; older students measure with standard units, calculate averages of several trials and graph results. Computational thinking includes using step-by-step procedures, like a sorting rule for classifying rocks.

Stem: “We measured… The difference was… On average…”

6. Constructing explanations and designing solutions

Explanations answer “why” or “how” with evidence. K–2 students explain using their observations (“The ice melted faster in the sun because the sun warmed it”). In 3–5, students use evidence from their investigations and texts to explain phenomena. On the engineering side, students design, test and improve solutions, from a shade structure in K to a device that reduces the impact of a falling object in 4th or 5th grade.

Stem: “This happens because… Our evidence is…”

7. Engaging in argument from evidence

Arguing in science means supporting a claim with evidence and reasoning and responding respectfully to other ideas. Many teachers use a claim-evidence-reasoning (CER) structure. In K–2, this starts with “I think… because I saw…” and listening to classmates. In 3–5, students compare explanations or design solutions and defend their choice with data.

Stem: “I agree/disagree with… because… The evidence that supports this is…”

Quick activity: Present two different claims about the same data and have partners decide which is better supported, then share why.

8. Obtaining, evaluating and communicating information

Students gather information from books, articles, videos and experts, judge whether it’s useful and share what they learned. This is where science and literacy meet: reading informational text, writing explanations and giving short presentations. Our post on graphic organizers for writing includes an informational organizer that fits science write-ups well.

Stem: “According to… I learned… This source is helpful because…”

Making room for the practices in a short science block

Many elementary schedules give science only 30 to 45 minutes a few times a week, and sometimes less. You don’t need long labs to use the practices. A five-minute “notice and wonder” at the start of a lesson builds questioning. A quick drawing of a model before and after a reading builds modeling. A two-minute partner talk with a claim and one piece of evidence builds argument. Small, regular moves add up over a year.

Integration helps too. Data from a science investigation can be the graph students analyze in math. An informational text on the same topic can be the reading for a literacy lesson, and an explanation of the results can be the writing assignment. When science shares time with other subjects, the practices travel with it.

How the practices work in a unit

The practices aren’t a sequence to march through. A unit on plant needs might start with questions (practice 1) about a wilted plant, move to a model (2) of what a plant needs, an investigation (3) with light and water, data (4 and 5) on growth, an explanation (6) and a discussion (7) of results, and a short informational reading (8) that connects to farming. Each lesson highlights one or two practices.

When you plan, start with the performance expectation, which already names the practice it targets. A code like 2-LS2-1 tells you the grade (2), the domain (Life Science) and the core idea (LS2), and the performance expectation spells out the practice students use. Our guide on how to align lessons to standards shows how to unpack it.

Supporting all learners

The practices give every student a way in. Hands-on investigations, drawings and models let students show understanding without relying only on reading and writing, which helps English learners and students who struggle with print. Provide sentence stems, word banks with pictures and roles in group work. For students with IEPs or 504 plans, the team decides on accommodations; build them into investigations from the start rather than adding them later.

For the full structure of the standards, the core ideas by grade and how the three dimensions connect, visit our NGSS science standards guide.

FAQ

What are the 8 science and engineering practices?

1) Asking questions and defining problems, 2) developing and using models, 3) planning and carrying out investigations, 4) analyzing and interpreting data, 5) using mathematics and computational thinking, 6) constructing explanations and designing solutions, 7) engaging in argument from evidence, and 8) obtaining, evaluating and communicating information.

What are the three dimensions of NGSS?

Science and Engineering Practices (what students do), Disciplinary Core Ideas (the content) and Crosscutting Concepts (big ideas like patterns and cause and effect that connect all sciences). Performance expectations combine all three.

Do I have to teach all eight practices in every lesson?

No. Most lessons focus on one or two practices. Over a unit, students should use several, and over a year, all eight.

How do the practices look different in K–2 and 3–5?

In K–2, students make observations, draw simple models, compare and describe patterns with adult support. In 3–5, they plan fair tests, use measurements and graphs, and support claims with evidence and reasoning more independently.