Person skilled in the art

The person skilled in the art is the reference figure of patent law. It is a notional practitioner, ordinarily qualified in the technical field concerned, who has the common general knowledge of the specialty and access to the state of the art, but who has no inventive imagination. The skilled person serves as the objective yardstick for assessing inventive step, sufficiency of description and the meaning of the claims. The notion appears in Article L. 611-14 of the French Intellectual Property Code and in Article 56 of the European Patent Convention.

Defining the person skilled in the art

First, the skilled person is defined by the technical field in which the problem solved by the invention arises, not by the field of the solution. Second, the skilled person possesses the common general knowledge of that field, as found in textbooks, reference works and routine practice, and is deemed to know all the relevant prior art. Third, the skilled person may be a team of specialists where the problem spans several disciplines. The level of skill is that of an average practitioner, neither a leading expert nor a novice. The French provisions can be consulted on Légifrance.

The role of the person skilled in the art

Inventive step is assessed by asking whether the invention followed in an obvious manner from the state of the art for the person skilled in the art. In the EPO problem and solution approach, the question is whether the skilled person would have been prompted to modify the closest prior art so as to arrive at the invention. Sufficiency of description is assessed by verifying that the skilled person can carry out the invention without undue burden. The claims, finally, are construed through the eyes of the skilled person.

Key points

In practice, the definition of the skilled person is a major battleground in litigation: a skilled person defined too broadly makes the invention obvious, one defined too narrowly makes it inventive. The parties rely on experts and technical consultants to assist the court. The firm builds this argumentation in revocation and infringement actions, as presented on the page patent nullity action.