Setting up a Fair Test

Caleb was the starter for a fair test to show the class how variables can affect the final outcomes.

We were looking to see where  the balls would end of up after being let go down two similar ramps. 
We wanted to see how far the balls would go.
We wanted to think about anything that could affect the outcomes of the balls being released and how they travelled.

We discovered that the floor was uneven as the ping pong ball went in a completely different direction to the large marble.  Even when we swapped slopes, the marble moved away from the direction the ping pong ball ws going in.
The balls did not travel the same distances, the marble always went the furtherest.
The marble deviated further from the straight line we were expecting it to travel.

Some of the variables we considered were these: 

• that the balls were unevenly shaped
• Caleb could let the balls go at at different time
• the texture of the carpet in walked on areas
• Caleb breathing on the balls
• different slopes on the ramps
• uneven ramp lengths
• movement of people in the room could affect the floor
• Caleb pushed one or both of the balls
• different slopes of the floor
• gravity affecting the balls in different ways
• the friction of the carpet against the heavier marble
• friction affecting the plastic of the ping pong ball.
• different students letting the balls go

Overall, it was an elightening activity when considering how many things can affect the outcome of one experiment.