MS-ETS1-1: Defining Criteria and Constraints
Also called NGSS MS-ETS1-1 · Topic: Engineering Design · Engineering, Technology, and Applications of Science
The Official Wording
Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What MS-ETS1-1 Means in Plain English
Students take a design problem and define it precisely: the criteria a solution must meet to count as a success, and the constraints that limit it, like cost, time, materials and space. They use measurements and science ideas to make each one specific.
They also ask how a solution could affect people or the environment, since that can rule some ideas out. This builds on 3-5-ETS1-1 and leads to comparing solutions (MS-ETS1-2) and, in high school, HS-ETS1-1.
MS-ETS1-1 I Can Statements
- I can write criteria that can be measured.
- I can list the constraints that limit a design.
- I can explain how science and side effects shape a design problem.
MS-ETS1-1 Worked Example
A class sharpens a fuzzy goal, keeping the classroom basil alive over a four-day weekend, into a problem it can actually test.
What exactly must a self-watering system do to keep our basil healthy over a four-day weekend?
Set It Up: Four potted basil plants, a kitchen scale, a ruler, a soil moisture meter and a notebook for the class problem statement.
- Write a first draft of the problem.Draft: keep the plants alive
- Weigh each pot every morning for three school days without watering.Each pot loses about 40 g of water a day
- Use that loss, plus a safety margin, to set a measurable criterion.Supply at least 200 mL over 4 days
- Add a second criterion from the moisture meter.Meter reads 4 to 7 on its 10-point scale all weekend
- List the constraints with the teacher and custodian.Under $5, no outlet, fits a 15 cm windowsill
- Note side effects the design must avoid.No drips on the heater, reuse old containers
The vague goal became two measurable criteria and a clear list of constraints, so every design idea could be judged against the same targets.
Why it works: Plants lose water through their leaves and soil every day, so measuring that loss tells engineers how much water a solution has to supply.
Common Mistakes with MS-ETS1-1
Writing criteria you cannot measure
“The plants should look happy.”
Try this: Turn each goal into a number or a clear test, like at least 200 mL delivered or a meter reading of 4 to 7.
Mixing up criteria and constraints
Listing “must cost under $5” as a goal of the design
Try this: Criteria describe what success looks like. Constraints are the limits you work within, like budget, time, space and materials.
Jumping straight to a solution
“Let's build a bottle drip feeder!” before any problem is written
Try this: Define the problem first. Writing criteria before choosing a design keeps the team open to ideas that might work better.
Where MS-ETS1-1 Fits
Practice MS-ETS1-1
Quick Check
- Is “must cost less than $5” a criterion or a constraint?
- Why weigh the pots before designing anything?
- Name one possible impact on people or the environment this design should consider.