HS-ETS1-4: Testing Solutions with Computer Simulations
Also called NGSS HS-ETS1-4 · Topic: Engineering Design · Engineering, Technology, and Applications of Science
The Official Wording
Use a computer simulation to model the impact of proposed solutions to a complex real-world problem with numerous criteria and constraints on interactions within and between systems relevant to the problem.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What HS-ETS1-4 Means in Plain English
Students use a computer simulation to try out possible solutions to a complicated problem before anyone builds them. They change the design inside the model, run it many times and compare how each version affects the connected systems, such as traffic, air quality and safety.
The problem has many criteria and constraints, so no single number decides. Students also judge the model itself, what it leaves out and how far to trust it. It builds on HS-ETS1-3 and pairs with the resource models of HS-ESS3-3.
HS-ETS1-4 I Can Statements
- I can change a design inside a simulation and run it.
- I can compare simulated results across several criteria.
- I can explain what a simulation leaves out.
HS-ETS1-4 Worked Example
A simulation study a class can run in NetLogo's free Traffic Grid model of a busy street grid.
Which traffic signal plan moves cars through a busy grid with the least waiting and idling?
Set It Up: NetLogo's free Traffic Grid model on school laptops, a results table and three signal cycle lengths to test.
- Run the default plan five times and average the results.Baseline wait time and stopped cars
- Shorten the signal cycle and run five more times.Shorter waits at each red
- Lengthen the cycle and run five more times.Longer queues build at each red
- Raise the number of cars to rush-hour levels and repeat each plan.The best plan changes with traffic volume
- Compare the plans on wait time and on stopped cars, a stand-in for idling exhaust.No plan wins at every traffic level
The shorter cycle cut waiting in normal traffic, but at rush hour a longer cycle moved more cars, so the class recommended switching plans by time of day.
Why it works: A simulation lets many designs be tested quickly and cheaply, and its interacting parts reveal effects, like queues spilling back, that a single calculation would miss.
Common Mistakes with HS-ETS1-4
Trusting one run
Picking a plan after a single simulation
Try this: Simulations with random parts give different results each run, so repeat each plan several times and compare averages.
The model is reality
“The simulation proves this will work downtown.”
Try this: List what the model leaves out, like pedestrians, turning cars or crashes, and say how that limits your conclusion.
Optimizing one criterion
Choosing the plan with the shortest car wait and stopping there
Try this: Check every criterion, such as idling, walker safety and cost, because the fastest plan for cars may fail the others.
Where HS-ETS1-4 Fits
Practice HS-ETS1-4
Quick Check
- Why run each simulation setting several times?
- Name one thing a traffic model might leave out that matters in real life.
- Why test solutions in a simulation before building them?