3-PS2-2: Predicting Motion from Patterns
Also called NGSS 3-PS2-2 · Topic: Forces and Interactions · Physical Science
The Official Wording
Make observations and/or measurements of an object’s motion to provide evidence that a pattern can be used to predict future motion.
Clarification statement: Examples of motion with a predictable pattern could include a child swinging in a swing, a ball rolling back and forth in a bowl, and two children on a see-saw.
Assessment boundary: Assessment does not include technical terms such as period and frequency.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 3-PS2-2 Means in Plain English
Third graders watch or measure something that moves in a repeating way, such as a swing, a seesaw or a rocking chair. They record what it does again and again, spot the pattern, and use that pattern to say what the object will do next.
Students describe the pattern in everyday words, like “it takes the same time to come back every time,” without terms such as period or frequency. This builds on 3-PS2-1 forces and connects to patterns in waves in 4-PS4-1.
3-PS2-2 I Can Statements
- I can record how an object moves over and over.
- I can find a pattern in a repeating motion.
- I can use a motion pattern to predict what happens next.
3-PS2-2 Worked Example
A playground test with one swing, a backpack and a stopwatch.
Can we predict how many times a swing goes back and forth in 30 seconds?
Set It Up: A playground swing with a backpack set on the seat, a chalk mark on the ground, a stopwatch, and a clipboard for tallies.
- Pull the swing back to the chalk mark and let go without pushing.Same start every time
- Count each full trip out and back for 30 seconds.Try 1: 10 trips
- Repeat twice from the same chalk mark.Try 2: 9 trips. Try 3: 10 trips
- Predict the count for a fourth try, then test it.Prediction: about 10. Result: 10
- Start from a lower mark and count again.Still about 10 trips
The swing made about 10 trips every 30 seconds, so the class could predict the next count before trying it.
Why it works: A swing moves in a repeating pattern, and a pattern that stays steady lets you predict where the motion goes next.
Common Mistakes with 3-PS2-2
Thinking a bigger pull-back means more trips
“If I pull it way back, it will swing more times.”
Try this: Test it: count trips from a low start and a high start. The count barely changes, though the high start swings wider.
Pushing during the test
A friend gives the swing an extra shove halfway through
Try this: Let the swing go and keep hands off until the timer stops, so nothing new changes the motion after the start.
Predicting from one try
“It went 9 times, so it always goes 9.”
Try this: Run at least three tries and look at what the counts have in common. A pattern shows up across many tries, not one.
Where 3-PS2-2 Fits
Practice 3-PS2-2
Quick Check
- A swing makes 10 trips in 30 seconds three times in a row. What do you predict next time?
- Name another motion that repeats in a pattern.
- Why start the swing from the same mark every time?