Despite their many different faces, the person skilled in the art (PSITA), also referred to as the "person having ordinary skill in the art", is an important character in the field of patents.

The PSITA is a legal concept found in many patent laws, and it is used in various aspects of patent examinations worldwide. In most jurisdictions, it is a hypothetical person who is presumed to be a skilled practitioner in a technical field, with average knowledge and ability, and who is aware of what is common general knowledge in the art at a given relevant date.

The main goal of this legal fiction is to provide a standard for determining whether a patent application satisfies the patentability requirements of having an inventive step and sufficient disclosure. This concept is fundamental in patent law since it prohibits the patentability of trivial inventions, preserves the patentability of worthy ones and guarantees the principle of the patent system to impart knowledge.

The level of knowledge and aptitude of the PSITA varies from one field to another and must be defined on a case-by-case basis. Patentees and patent opponents may be tempted to consider the PSITA as a "newbie" or an expert, respectively. However, even if the standard skills required for the PSITA is different across jurisdictions, it is commonly admitted that the PSITA:

  • is familiar with the "ordinary" technical knowledge in the relevant art;
  • does not know "all" the prior art (even if they have access to it); and
  • above all, would not engage in creative thinking.

The PSITA can also be plural. As technologies have evolved, the average number of inventors per patent has increased in recent decades. The ordinary inventor today is a joint inventor, who invents as part of a team. Accordingly, the PSITA can also be defined as a group of persons, such as a research or production team, rather than a single person.

Interestingly, while the concept of the PSITA as a standard has never stopped evolving, it could become much harder to define it in the next few years because of artificial intelligence systems, which have become more prevalent and more advanced. Their use offers unlimited possibilities to inventors, as processing incredible amounts of data or carrying out large-scale simulations can be done very quickly. Consequently, it will be central for the courts to determine whether the PSITA would have access to these powerful tools and would have used them in the same way to solve technical problems.

For further information on this topic please contact Eric Bilhère at GEVERS by telephone (+32 2 715 3711) or email ([email protected]). The GEVERS website can be accessed at