Section 9 - Planning an Experiment

Question 1

What does ‘repeatable’ mean?

Answer 1

Repeatable means that if the same person repeats the experiment using the same methods and equipment, they will get the same results.

Question 2

What does ‘reproducible’ mean?

Answer 2

If someone different does the experiment, or a slightly different method or piece of equipment is used, the results will still be the same.

Question 3

What do ‘valid’ results do?

Answer 3

Answer the original question

Question 4

What do ‘valid’ results do?

Answer 4

Answer the original question

Question 5

How do you achieve valid results?

Answer 5

Control all the variables to make sure you’re only testing the thing you want to

Question 6

What are variables?

Answer 6

Variables are qualities that have the potential to change

Question 7

What are the four things that you need to consider when thinking about experimental design?

Answer 7

1) Only one variable should be changed
2) All the other variables should be controlled
3) Negative controls should be used
4) Repeat the experiment at least three times

Question 8

Why are negative controls used?

Answer 8

Negative controls are used to check that only the independent variable is affecting the dependent variable. Negative controls aren’t expected to have any effect on the experiment.