Sometimes two people build different designs for the same job. You can test both and use the data to compare them.
Mia tests two boat designs. Boat A holds 5 coins. Boat B holds 9 coins. Mia looks at the data and picks Boat B.
No design is perfect. One design might be strong. Another might be light or fast. Data helps you pick the best one.
Test both designs, compare the data, then pick the best one.
When you test two paper planes, what should you write down?