Step-by-step explanation:
To see if using a cell phone actually impairs driving skills, it is necessary to conduct an experiment to test this hypothesis. We can define an experiment as a controlled test to affirm a certain behavior (hypothesis). This is an important procedure to discover the causes and effects that will be important to complete an experiment, so when performing this test it is necessary for a researcher to manipulate a variable in order to find out what its effects are on another variable, so that conclusions about cause and effect.
Every experiment must have an independent variable and a dependent variable. The independent variable is configured as the experimental situation manipulated by the researcher, and the dependent variable is defined as the behavior that the researcher tries to predict. In this question, then, the independent variable is the use of the cell phone, and the dependent variable is the number of collisions.
Therefore, to be valid, an experiment must have an experimental condition and a control condition.