Isolating the Variable

For the SMASH day, we did an activity where we had to make a small boat and try to make it hold as much weight as it could without sinking.
The activity isolated design as the variable because we started with the same materials, the same rules for everybody and we put the same kind of weight on the boat. We tested the boats on the same water.
The variables that were not controlled were mainly the design, how big you made the boat, where you put the straws. But also where you put the weights, and how you put them.
Every variable affected the outcome!