Question

determine whether the description corresponds to an observational study or an experiment. research is conducted to determine if there is a relation between brain cancer and use of cell phones. does the description correspond to an observational study or an experiment? ○ experiment ○ observational study

Explanation:

In an observational study, researchers observe and measure variables without interfering or manipulating them. Here, to study the relation between brain cancer and cell phone use, researchers would observe existing groups (those who use cell phones and those who don't, or with different usage levels) without assigning or controlling cell phone use (which would be unethical and impractical to manipulate for such a study). An experiment involves manipulating an independent variable (e.g., assigning people to use cell phones in a controlled way), which isn't feasible here. So this is an observational study.

Answer:

Observational study