The defendant is in breach of duty towards the claimant if their conduct fell short of the standard expected under the circumstances.
The standard of care is defined as the measures that a reasonable person (in the circumstances of the defendant) take to reduce the risk of harm.
This is an objective standard where the 'reasonable person' test is applied to determine if the defendant has breached their duty of care.
It is important to note that the claimant's knowledge of the defendant's lack of experience in the skill he is exercising does not result in the standard being lowered.
The student argued that the instructor was aware of her lack of experience, but the Court of Appeal refused to accommodate this fact in their decision on the standard of care expected from her.
While no allowance is made for novices, the courts are prepared to lower the standard of care expected of children, on account of their age.
However, in certain situations it is unlikely that a certain event could take place without the defendant's negligence, for example if a surgeon left a scalpel in the patient's body.
In such cases, it is said that "the thing speaks for itself" (res ipsa loquitur), and it is for the defendant to show that the fact causing the damage was not attributable to his negligence.