In appellate court decisions, negligence suits have historically been analyzed in distinct stages. First, the defendant must have had a duty of care towards the claimant. The courts have long established that all persons have a duty to use that degree of care that an ordinarily prudent person would have used under the circumstances, so that, at trial, the existence of the "duty" is predetermined. However, the constitutional right to jury trial on fact questions has established overwhelmingly, at least in the US, that the determination of whether the behavior of a particular defendant in any given case constitutes negligence is ordinarily a unique question of fact for jury determination.  Proving negligence does not, alone, support an award of damages. Second, obviously from the definition above, the claimant must show that the defendant has breached that duty by not exercising reasonable care. The plaintiff must further show that the defendant's negligence contributed to cause harm to the claimant. Fourth, the harm must not be too remote a consequence of the negligence; that is, the negligence must be a "proximate cause" of the harm. Finally the claimant must be able to establish what kind of damages, or compensation, he should get for his or her harm. "The broad agreement on the conceptual model," writes Professor Robertson of the University of Texas, "entails recognition that the five elements are best defined with care and kept separate. But in practice," he goes on to warn, "several varieties of confusion or conceptual mistakes have sometimes occurred."