Avoiding The Hindsight Trap In The Context Of A Patent Obviousness Analysis

While courts have often warned that hindsight bias should be avoided when assessing whether a patented invention would have been obvious to the skilled person, the application of this principle can be challenging in practice.

Section 28.3 of the Patent Act provides that the subject matter of a claim in a patent application must not have been obvious to a person skilled in the art as of the claim date. When the validity of a patent is challenged on the basis of obviousness—which is the case in almost all patent cases where validity is at issue—Canadian courts apply the well-known four-part obviousness test established by the Supreme Court of Canada in Apotex Inc v Sanofi-Synthelabo Canada Inc¹ Steps one to three involve identifying the state of the art, determining the inventive concept of the claim, and identifying the differences between the inventive concept and the state of the art. Step four is to assess whether the differences would have been obvious to the