The many faces of the ‘Person Skilled In The Art’ (PSITA) 

Despite his many short names like PHOSITA, POSITA and PSITA the “person skilled in the art” enjoys the legal fiction of being a hypothetical person who is presumed to know his technical field like a professional with average knowledge and ability, and he is well-versed with the common general knowledge in the art at a given relevant date of the claimed invention.  

Another important aspect of his legal personality is that he is equally adored by patentee and patent opponents alike to support their case. In the words of Mueller, the proponent of validity usually will attempt to establish as low a level of skill standard as possible, such that the invention would have been considered non-obvious by the largest possible number of persons, while the challenger of validity typically will seek to raise that level. Additionally, the PSITA changes its status from singular to plural depending on if invention is work of an individual or it is work of a team. A group of persons or team involved in development of the invention can also be treated as PSITA for the purpose of establishing inventive step. He is a person having ordinary skill in the art, yet he plays a crucial role in the field of patentability assessment in every jurisdiction. Interestingly, he mimics its appearance on a case-to-case basis.  

Judicially created person  

A judicially created legal fiction, as a hypothetical person, PSITA changes its personality from country to country. The foundation of every patent law for assessment and determination of inventive step rests deep in the understanding of what the PSITA would think about the claimed invention.  

He has taken many faces worldwide if we go through the judicial understanding of this person. Justice Jacob referred him as a “nerd” when he said, “It is settled that this man, if real, would be very boring – a nerd”. For Lord Reid, “He is supposed to have an unlimited capacity to assimilate the contents of, it may be, scores of specifications but to be incapable of scintilla of invention.”  Justice Laddie, who discussed the nature of the skilled man in the art in the case of a Pfizer patent and called him a non-inventive skilled man. 

 If in the United States, the skilled person is known as “a person having ordinary skill in the art” (PHOSITA); this definition is understood from the case of Hotchkiss v. Greenwood where the court mentioned that the invention was too simple for “an ordinary mechanic acquainted with the business.” No further elaboration on the scope and standards of skills of the ‘ordinary mechanic’ was made in this case. In the words of Mueller, this ‘ordinary mechanic’ of Hotchkiss could be regarded as a historic ancestor of the PHOSITA, i.e. “person having ordinary skill in the art.”  

In Europe, he is also called the “person having ordinary skill In the art”. The birth of this hypothetical person is attributed to Justice Laddie who discussed the nature of the skilled (but non-inventive) man in the art in the case of a Pfizer patent, where he suggested that this notional skilled worker has more extensive knowledge of the prior art. He added general characteristics to his persona as a skilled man when he stated:  

“This is not a real person. He is a legal creation. He is supposed to offer an objective test ... He is deemed to have looked at and read publicly available documents and to know of public uses in the prior art. He understands all languages and dialects. He never misses the obvious nor stumbles on the inventive. He has no private idiosyncratic preferences or dislikes. He never thinks laterally. He differs from all real people in one or more of these characteristics. A real worker in the field may never look at the piece of prior art- for example he may never look at the contents of a particular public library- or he may be put off because it is in a language he does not know. But the notional addressee is taken to have done so.” 

The Position in India  

In India the journey of the definition of the PSITA can be traced from the first landmark case on obviousness in Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries, where the Supreme Court held that “Another test of whether a document is a publication which would negative existence of novelty, or an ‘inventive step’ is suggested, as under: Had the document been placed in the hands of a competent craftsman (or engineer as distinguished from a mere artisan), endowed with the common general knowledge at the ‘priority date’, who was faced with the problem solved by the patentee but without knowledge of the patented invention, would he have said, ‘this gives me what I want?’” [emphasis added] 

In this case, the PSITA is “a competent craftsman (or engineer as distinguished from a mere artisan), endowed with the common general knowledge at the priority date, who was faced with the problem solved by the patentee but without knowledge of the patented invention”. This case perhaps laid the foundation that ‘a competent craftsman’ could be regarded as a historic precursor of the PSITA, i.e. ‘person skilled in the art.’ in India. 

PSITA is not a dullard: IPAB  

Without referring to the supreme court ruling in Biswanath the Intellectual property Appellate Board (IPAB) in Sankalp Rehabilitation Trust v. Hoffmann La Roche addressed PSITA as being not a dullard when it said that “The PSITA is not described as either ‘ordinary’ or ‘average’ for the purpose of non-obviousness. He is not a dullard and has a certain modicum of creativity.” 

Definition of PSITA in TRIPS  

If we look at Article 29.1 of the TRIPS Agreement, we will find mention of the term person skilled in the art: “Members shall require that an applicant for a patent shall disclose the invention in a manner sufficiently clear and complete for the invention to be carried out by a person skilled in the art…”. 

Accordingly, as per the TRIPS mandate, members can apply the PSITA concept while understanding and investigating sufficiency of disclosure of the invention in the application to qualify the enablement requirement. Though no criteria to use the PSITA concept is laid down in TRIPS for determination of the inventive step, PSITA assumes a great relevance when one is dealing with the novelty, non-obviousness and disclosure criterions in the patent office examination and inventive step-related disputes in opposition or infringement cases. Due to the inherent difficulties tied to the everchanging qualities of the PSITA, the nature and persona of this hypothetical person is mimicked from one case to another. Therefore, it unlikely to come across one definition of PSITA acceptable to all jurisdictions. It is also unlikely to nail down what judicial precedents on domestic laws most countries would generally lay down when it comes to fixing the skill standard for the PSITA. 

PSITA under the Patents Act, 1970  

In the Indian context, the PSITA is not defined in the law, but a fleeting clue about his qualification is mentioned rather indirectly, in a ground of revocation under Section 64(h) where it is stated “that complete specification are not by themselves sufficient to enable a person in India possessing average skill in, and average knowledge of, the art to which the invention relates, to work the invention.” 

In other words, to prove the insufficiency/enablement ground, it is sufficient to contend that the description of the method or the instructions for the working of the invention as contained in the complete specification are not by themselves sufficient to enable a person in India possessing average skill in, and average knowledge of, the art. Accordingly, the person who possesses average skill in, and average knowledge of, the art is the person skilled in the art for the purpose of understanding the invention for the investigation of enablement. Additionally, that person should perform the invention based on the description in the specification without other assistance or further experiment. 

Attributes of a PSITA  

Though the judicial definition of the PSITA differ from country to country, the essential attributes to qualify as a PSITA in all the jurisdictions are more or less the same as: 

• He is familiar with the “ordinary” technical knowledge in the relevant art; 

• He does not know “all” the prior art (even if he has access to it); and 

• He would not engage in creative thinking. 

In Environmental Designs v. Union Oil, the Federal Circuit observed that “factors that may be considered in determining level of ordinary skill in the art include: 

1) The inventor’s educational background;  

2) The kinds of problems confronted in the art;  

3) Solutions found previously;  

4) The level of sophistication of the technology;  

5) The speed of innovation in the art; and  

6) The educational level of workers in the field.”  

However, all the courts would likely agree and caution that not all factors will be relevant in every case. The role of PSITA as an analyst of prior art during a non-obviousness examination and analyzing sufficiency of disclosures in applications is well recognized by Indian courts. But what persona PSITA adorn will be totally case-driven. 

Conclusion  

The basic question before the Controller and courts in India is whether “a person in India possessing average skill in, and average knowledge of, the art’ within the meaning of Section 64(h) for ascertaining enablement/sufficiency” is the same as the “person having ordinary skill in the art” within the meaning of Section 2(1)(ja) for the purpose of determining obviousness. Or, as the IPAB said, “the PSITA is not described as either ‘ordinary’ or ‘average’ for the purpose of non-obviousness. He is not a dullard and has a certain modicum of creativity.”  

If we look at the Patents Act ,1970 and the Patent Rules 2003, we find no definition on the person skilled in art for assessing inventive step of a claimed invention under Section 2(1)(ja). Several judgments in other jurisdictions and at the IPAB also investigated the abilities of the PSITA in number of cases. However, in the disputes relating to the investigation of inventive step before the IPAB and courts in India and elsewhere, the role of how a PSITA would view an application from the point of view of inventive step play a decisive role in grant or refusal of a patent.  

The IPAB raised the level of PSITA from dullard to a person who has a certain modicum of creativity.  

Interestingly, while the concept of the PSITA as a common acceptable standard has never stopped evolving as its use during resolution of tricky cases offers unlimited possibilities to inventors, opponents, and courts to determine whether the PSITA would have thought it obvious. When Justice Jacob said “the court must don the mantle of the skilled man,” he clearly suggested that those who are responsible for determining inventive step such as examiners or the Controller must put themselves in the shoe of a person skilled in the art before taking any decision to refuse or accept a patent on the ground of obviousness.