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 CR018002: A controlled experiment involving the drying of swimsuit fabric, in which the type of fabric changes but how large a piece of fabric you use and how wet the fabrics are to start with are held constant, can tell you if the type of fabric affects how long it takes the fabrics to dry.
A swimming team wants to select one of three fabrics for their new swimsuits. Each fabric is made of a different material. The team decides to do the following experiment:
They cut the same size pieces from each fabric and wet each piece with the same amount of water. They hang the pieces in the sunlight and they check every two minutes to see if any of the pieces are dry.
What can the team find out about the different fabrics from doing just this experiment?
- If the amount of water affects how long it takes the pieces of fabric to dry.
- If the type of fabric affects how long it takes the pieces of fabric to dry.
- If the amount of water and the amount of light affect how long it takes the pieces of fabric to dry.
- If the type of fabric, the amount of water, and the amount of light affect how long it takes the pieces of fabric to dry.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1460 | 2376 | 62% |
| Grades | |||
| 6–8 | 724 | 1289 | 56% |
| 9–12 | 731 | 1078 | 68% |
| Gender | |||
| Male | 717 | 1165 | 62% |
| Female | 726 | 1174 | 62% |
| Primary Language | |||
| English | 1304 | 2087 | 62% |
| Other | 120 | 228 | 53% |