Final answer:
Res Ipsa Loquitur is a legal doctrine used in negligence cases when the plaintiff cannot establish the specific cause of harm. It applies when the plaintiff does not control what caused the harm and the circumstances indicate it is more likely than not that the defendant was negligent.
Step-by-step explanation:
Res Ipsa Loquitur is a legal doctrine that applies in negligence cases when the plaintiff is unable to establish the specific cause of harm, but the circumstances surrounding the harm indicate that it is more likely than not that the defendant was negligent. This doctrine is used when the plaintiff does not have direct evidence of negligence but can rely on the inference that the harm would not have occurred without the defendant's negligence.
Res Ipsa Loquitur applies when the plaintiff does not control what caused the harm, and it would be unfair to require the plaintiff to prove the specific cause. It is not necessary for only the defendant to control what caused the harm, as long as the circumstances make it more likely that the defendant was negligent.