Person having ordinary skill in the art

In practice, PHOSITA is a set of legal fictions evolved over time. Since the obviousness of an invention is a basic question to ask when awarding a patent, similar tests can be found in many patent laws.

US patent law

A person having ordinary skill in the art is a legal fiction defined in the Patent Act of the United States. The PHOSITA is a test of "obviousness" which is one of the largest gray areas in patent law.

A patent may not be obtained though the invention ... if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made. (35 U.S.C. § 103 (A))

Comparison

Quite similar to the logic of "reasonable person" used in the common law of torts as a test of negligence, the PHOSITA is a hypothetical individual, neither a genius nor a layperson, created in the mind of a patent examiner or the jury to see if a claimed invention is too obvious to be patented.

Creation

During the examination of a patent application, the examiner tries to find out if that invention has already been invented by another person. If so, the patent application will be returned to the applicant to be narrowed or modified. If not, the examiner will bring out the PHOSITA test to check if that invention is so obvious that people in the trade will invent it with or without patent applicant's efforts. In the end, if the examiner can not discover a piece of prior art that may lead the PHOSITA to the invention, the United States Patent and Trademark Office (USPTO) is required by statute to award that applicant a patent.

Examiner properly relied upon prior art publication in rejecting claims for production of [certain antibodies] ... under [35 U.S.C. § 103], even though publication itself is not prior art against present claims, since publication establishes level of ordinary skill in art at and around time of present invention. Ex parte Erlich, 22 USPQ.2d 1463 (Bd.Pat.App. & Inter. 1992).

Capacity

The term "ordinary skill" is not rigidly defined. The requirements of a nuclear physicist of ordinary skill are surely different from a chef of ordinary skill. An invention that involves aerodynamics takes a different kind of "ordinary skill" from another that involves woodworking.

Factors that may be considered in determining level of ordinary skill in the art include
:# the educational level of the inventor;
:# type of problems encountered in the art;
:# prior art solutions to those problems;
:# rapidity with which innovations are made;
:# sophistication of the technology; and
:# educational level of active workers in the field.

Environmental Designs, Ltd. v. Union Oil Co., 713 F.2d 693, 696, 218 USPQ 865, 868 (Fed. Cir. 1983), cert. denied, 464 U.S. 1043 (1984).

The PHOSITA redux

Because patent examiners are usually under very heavy workloads, they may not be able to look beyond the patent database and a few other frequently consulted sources. From time to time, patents regarded as obvious by people in the trade are patent protected. Some holders of these questionable patents will file lawsuits against their competitors. If the defendant can prove the existence of a prior art that can render the patent obvious before the patent's application date, the patent will be invalidated.

One of the frequent criticisms of software patents is the large number of patents which seem to violate the PHOSITA standard, but which are nevertheless granted by the US Patent Office and other countries' patent offices, presumably due either to overworked or underqualified patent examiners, or due to deficient process in analyzing whether an invention is non-obvious.

Fictional example

Fred Flintstone saw his wife's wheel and reinvented the exact same round thing. Only this time he used a section of timber instead of rock. He filed an application to the Bedrock Patent Office. The patent examiner, Barney Rubble, wisely noticed there once was a similar but slightly different invention (prior art). This time our beloved Barney has to come up with a PHOSITA to see if Fred's invention deserves a patent.

What should an ordinary stone age automobile builder know? Barney has to decide what other things an automobile builder would do in cold winter days when the stone car company is closed due to the heavy snow.

He found Fred's invention quite obvious to the imaginary PHOSITA. So he established a prima facie case of obviousness. The burden of proof of non-obviousness shifted to poor Fred who was just as speechless as a piece of lumber. He failed to prove why that PHOSITA could not invent a wooden wheel from Wilma's rock wheel. Under the preponderance of the evidence rule, the Bedrock Patent Office refused to award Fred a patent.

Europe Patent Convention

Elsewhere

For example, the German Patent Act (Patentgesetz) requires that the invention "cannot be derived by a Fachmann from the state of the art in an obvious manner".¹

The word Fachmann (an ordinary German word meaning somebody who has professional knowledge in a field) is made specific by ständiger Rechtsprechung (usual court opinion) as a "specialist with average knowledge and talent whom one would ordinarily ask to seek a solution for the (objective) problem the invention deals with"²

¹ ("... wenn sie sich für den Fachmann nicht in naheliegender Weise aus dem Stand der Technik ergibt.", Art. 4 of the Patentgesetz).

² "Sachverständiger mit durchschnittlichem Wissen und Können, den man üblicherweise mit der Lösung der (objektiven) Aufgabe der Erfindung betrauen würde" (stRspr - BPatG Mitt. 84, 213, T 32/81 Abl. 1982, 225)

Incomplete implementations of the obviousness test

External links