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 CR023005: In an experiment involving two variables (X and Y) that could affect the outcome of the experiment, changing X and keeping Y constant allows you to find out the effect of X on the outcome of the experiment.
A student thinks that there are two variables (X and Y) that may affect the result of her experiment.
She decides to change only variable X and let variable Y stay the same.
What can the student find out about the effects of variables X and Y?
- If variable X affects the result of her experiment.
- If variable Y affects the result of her experiment.
- If both variables X and Y affect the result of her experiment.
- She cannot find out if either variable X or variable Y affects the result of her experiment.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1187 | 2371 | 50% |
| Grades | |||
| 6–8 | 541 | 1288 | 42% |
| 9–12 | 642 | 1074 | 60% |
| Gender | |||
| Male | 604 | 1162 | 52% |
| Female | 565 | 1173 | 48% |
| Primary Language | |||
| English | 1069 | 2083 | 51% |
| Other | 89 | 227 | 39% |