2. Breach of Duty

Reasonable Man Test – Breach of Duty

The courts use the reasonable man test to decide if someone is in breach of duty. In Blyth v Birmingham Waterworks, negligence was defined as "the omission to do something which a reasonable man would do, or doing something which a prudent and reasonable man would not." This is an objective test, based on an ordinary, competent person in the relevant activity.

Reasonable Standard – DIY

Someone doing DIY is judged against the standard of a reasonably competent amateur, not a professional working for reward (Wells).

Reasonable Standard – Learner Driver

A learner driver is judged against the standard of a reasonable qualified driver (Nettleship v Weston).

Reasonable Standard – Children

A child is judged against the standard of a reasonable child of the same age (Mullins).

Reasonable Standard – Professionals

A professional is judged against the standard of an ordinary competent professional in that field (Bolam), and this includes trainees (Wilsher v Essex).

Risk Factors – Size and Practicality

To decide what is reasonable, the courts weigh the seriousness of the risk against the practicality of taking precautions. They examine various risk factors to support their decision. Defendants must take reasonable steps but are not required to eliminate every potential risk, particularly where doing so would involve great expense (Latimer).

Risk Factor – Claimant’s Special Characteristics

If the claimant has special characteristics (e.g., disability or being a child) that make them more vulnerable, the reasonable man must take greater care (Paris).

Risk Factor – Social Importance of Activity

If the defendant's activity is socially important, the reasonable man can take greater risks (Watt).

Risk Factor – Unforeseeable Risks

The reasonable man is not expected to guard against unforeseen risks (Roe).