Practice of science

Fair Test Laboratory

Change one variable, measure one outcome, and keep everything else the same.

Independent variableDependent variableControlled variables

Challenge 1: Identify the variables

A student investigates whether steeper ramps make a ball reach the bottom faster.

In progress

Independent variable — what is changed?

Dependent variable — what is measured?

Controlled variables — what stays the same?

Choose one answer in each box.

Select the experiment in which only the ramp slope changes.

Select a design to receive feedback.

Choose every action that makes the evidence more reliable.

Repeat each ramp angle three times Calculate an average time Use a different ball for every trial Guess times that look unusual

Select the actions you recommend.