Final answer:
A controlled experiment, specifically an experimental study, is the sound and established way to prove or disprove the value of a new medication or treatment.
Step-by-step explanation:
The sound and established way to prove or disprove the value of a new medication or treatments is a controlled experiment. This includes an experimental study, which involves dividing participants into two groups - one receiving the new drug and the other receiving a placebo. By comparing the outcomes of the two groups, researchers can determine the effectiveness of the new medication.