A student conducts an experiment to determine how the temperature of water affects the time for sugar to dissolve. In each trial, the student uses a different amount of water and a different temperature of water.

Question

What is wrong with this experimental design?

Responses

The student did not change enough independent variables.
The student did not change enough independent variables.

The student changed more than one independent variable.
The student changed more than one independent variable.

The student does not have a dependent variable.
The student does not have a dependent variable.

The student needs to perform more trials.
The student needs to perform more trials.

Answer 1

The correct response to identify the problem with the experimental design is:

The student changed more than one independent variable.

In this experiment, the student is varying both the amount of water and the temperature of the water. However, to properly assess how temperature affects the time for sugar to dissolve, the only independent variable should be the temperature of the water. By changing both variables at the same time, it becomes impossible to determine which factor is influencing the dissolution rate of sugar.