Item CV024005: An experiment in which variable X is allowed to vary and variables Y and Z are held constant could tell you if variable X has an effect on the result of the experiment.

A student thinks that there are three variables (X, Y and Z) that may affect the result of her experiment.

What should the student do to find the effect of variable X on the result of the experiment?

  1. Change variable X and keep variables Y and Z the same.
  2. Change variables Y and Z at the same time and keep variable X the same.
  3. Change variable X and Y at the same time and keep variable Z the same.
  4. Change variables X, Y, and Z at the same time.

Distribution of Responses

Chart showing distrubtion of responses for Item CV024005

Percent of students responding correctly

Grades 6–844%
Grades 9–1259%
Primary Language is English52%
Primary Language is not English40%

View data table