Original Project
Control of Variables
If more than one variable changes at the same time in an experiment, the outcome of the experiment may not be cl…
Item CV030001: In an experiment involving three variables (X, Y, and Z) that could affect the outcome of the experiment, changing X and keeping Y and Z constant allows you find out the effect of X on the outcome of the experiment.
A student thinks that there are three variables (X, Y and Z) that may affect the result of her experiment.
She decides to change only variable X, and let variables Y and Z stay the same.
What is the student trying to find out?
- If variable X affects the result of her experiment.
- If variables X and Y affect the result of her experiment.
- If variables Y and Z affect the result of her experiment.
- If variables X, Y, and Z affect the result of her experiment.
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 2556 |
6–8 n = 1377 |
9–12 n = 1165 |
Male n = 1257 |
Female n = 1277 |
English n = 2203 |
Other n = 314 |
||
| A. | If variable X affects the result of her experiment. | 67% | 57% | 79% | 64% | 71% | 69% | 56% |
| B. | If variables X and Y affect the result of her experiment. | 8% | 10% | 6% | 10% | 7% | 8% | 12% |
| C. | If variables Y and Z affect the result of her experiment. | 16% | 19% | 11% | 17% | 14% | 15% | 21% |
| D. | If variables X, Y, and Z affect the result of her experiment. | 9% | 13% | 4% | 9% | 8% | 9% | 11% |