1. can you spot the differences?
Controls & Variables
can you spot the differences?

2. pattern or size affect how well it works??
Does an umbrella’s
pattern or size affect how well it works??
it’s gonna rain!

3. Variables are parts of an experiment that change
Variables are parts of an experiment that change. There are two main kinds.
what’s different?

4. Independent variables are the part of the experiment that YOU change
what did you change?

5. In this experiment, the
is the
independent variable?
what did you change?

6. are the part of the experiment
Dependent variables
are the part of the experiment
that you measure
what would you measure?

7. In this experiment, the
is the
dependent variable?
what would you measure?

8. The DEPENDENT variable depends on the INDEPENDENT variable.

9. Which is right?

10. Does the pattern depend on performance?
Does performance depend on the pattern?

11. Control variables are parts of the experiment that
don’t change
what stays the same?

12. what stays the same? What would have to be the same for each
umbrella test that you do?
what stays the same?

13. What if some of the umbrellas were broken or if there was different amounts of rain every time you did a test?
which umbrella is best?

14. PRACTICE
SCENARIO

15. How would you figure out which of two fertilizers helps a plant grow more?

16. What would your experiment be
What would your experiment be? What are the independent and dependent variables?

17. What if it turned out that fertilizers might be bad for the plants
What if it turned out that fertilizers might be bad for the plants? How would you know?

18. You need a plant that doesn’t have any fertilizer at all
You need a plant that doesn’t have any fertilizer at all. That way you know if the fertilizers helped or hurt at all.

19. The control group is what you compare your experiments to and is used as a baseline.

20. Normally, the control group is the group that you don’t do anything to (i.e. no fertilizer at all)