The Retrospective Risk in the Analysis of Inventive Step,
In the examination of patentability, the inventive step is one of the most complex and debated requirements. Determining whether an invention “is not obvious” to a person skilled in the art involves a legal and technical assessment subject to a recurring danger: the retrospective analysis, also known as hindsight bias.
1. The Nature of the Retrospective Risk
The retrospective risk arises when the obviousness of an invention is assessed with knowledge of the result already achieved, leading to the mistaken conclusion that a solution was “evident” when, in fact, it was not before being discovered. This psychological bias can affect even the most experienced examiners and judges, who may unconsciously reconstruct the inventive process with information the inventor did not originally possess.
As Carlos Fernández-Novoa explains, the retrospective risk “distorts the objective assessment of creative ingenuity, confusing the logic of hindsight with the ex ante inventive effort” (La protección de las invenciones industriales, Civitas, 2005).
2. The European Approach: The Objective Technical Problem
The European Patent Convention (EPC) and the case law of the European Patent Office (EPO) have developed the so-called problem–solution approach precisely to avoid hindsight bias. According to Decision T 24/81 (ABZ/Derivatives) and subsequent rulings of the Technical Board of Appeal, this approach requires:
- Identifying the closest prior art.
- Determining the objective technical problem to be solved.
- 3. Evaluating whether, starting from that problem, the skilled person would have arrived at the claimed solution without inventive effort.
This method forces the examiner to reconstruct the reasoning without knowing the final result, thus avoiding the advantage of hindsight. In Decision T 564/89, the EPO reaffirmed that “the assessment of inventive step must not be made with the benefit of hindsight but by placing the skilled person in the position prior to the invention.”
3. U.S. Jurisprudence: The KSR v. Teleflex Case.
In the United States, the Supreme Court, in the landmark decision KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), reformulated the analysis of obviousness under Section 103 of the Patent Act, criticizing the rigidity of the former “Teaching–Suggestion–Motivation (TSM)”.
However, the Court itself warned that such flexibility “should not be confused with hindsight reasoning.” It emphasized that judges must take care not to deem an invention obvious merely because, once known, it appears simple or predictable.
Doctrinally, Donald S. Chisum notes that hindsight bias is “the most common pitfall in the obviousness inquiry,” since “an invention often seems obvious only after it has been revealed” (Chisum on Patents, §5.04[1]).
4. Preventing the Bias in Legal Practice
Avoiding hindsight bias requires the application of structured and objective criteria. Both EPO and U.S. jurisprudence coincide in that the assessment of inventive step must be made from the standpoint of the skilled person before the invention, disregarding any knowledge or effects that arose later.
Courts also recommend relying on technical and expert evidence to demonstrate how a person skilled in the art would have reasoned at the priority date not how the invention appears once its success is known.
5. Final Reflection,
Retrospective bias undermines the very essence of patent protection: rewarding genuine inventive activity.A rigorous inventive-step analysis must preserve objectivity, ensuring that hindsight logic does not replace the ex ante technical judgment. Both in Europe and America, doctrine and case law converge on a fundamental principle: an invention should not be considered obvious merely because it is now known.
References.
- Chisum, D. S. (2024). Chisum on Patents. LexisNexis, §5.04[1].
- Fernández-Novoa, C. (2005). La protección de las invenciones industriales. Civitas, Madrid.
- Cornish, W. R., & Llewelyn, D. (2019). Intellectual Property: Patents, Copyright, Trade Marks and Allied Rights (9th ed.). Sweet & Maxwell, London.
- European Patent Office (EPO), T 24/81 (ABZ/Derivatives), OJ EPO 1983, 133
- European Patent Office (EPO), T 564/89, OJ EPO 1991, 533
- KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007).
- World Intellectual Property Organization (WIPO). (2015). Guide to Patent Examination and Inventive Step Analysis. Geneva