a) Decisions before G 2/21

In reaching its decision on "Reliance on a purported technical effect for inventive step (plausibility)" the Enlarged Board referred to a selection of more recent decisions as examples for different approaches taken by the boards with regard to the acceptance of a patent applicant’s or proprietor’s reliance on an asserted technical effect (point 64 of the Reasons), which the development of the earlier case law appeared to culminate in. The Enlarged Board found that while these decisions used the terminological notion of "plausibility", the cited decisions appeared to show that the particular board of appeal focussed on the question whether or not the technical effect relied upon by the patent applicant or proprietor was derivable for the person skilled in the art from the technical teaching of the application documents (G 2/21, OJ 2023, A85, point 72 of the Reasons).

In T 1639/07 the board held that the objective technical problem must be derived from physical, chemical etc. effects directly and causally related to the technical features of the claimed invention (see also T 584/10, T 2297/10, T 1199/16, T 1341/16, T 2622/19, T 2217/19). The board in T 2622/19 stated that otherwise the notional skilled person could virtually pose their own "objective problem". This could lead to an inadmissible hindsight bias whereby the "person skilled in the art" within the meaning of Art. 56 EPC could then confront themselves with their "subjective" technical problem to be solved (see also chapter I.D.6 "Ex post facto analysis").

In T 377/14 the board, referring to T 344/89, held that the problem did not have to be explicitly disclosed in the application as filed; it sufficed if it was foreshadowed therein (see also T 478/17)

In T 31/18 the board held that the technical effect or problem being solved by the claimed subject-matter must either be explicitly mentioned in the application as filed or at least be derivable therefrom, but not necessarily originally supported by experimental evidence. It could indeed not be expected from a patent applicant to include an extensive amount of experimental evidence corresponding to all technical features which could possibly be claimed in the application as filed and which could possibly constitute a future distinguishing feature over the closest prior art, since said closest prior art and its technical disclosure may not be known to the applicant at the filing date of the application.

In the context of reliance on post-published evidence, a number of decisions had also already considered whether an alleged effect could be derived from the application as filed. In T 861/08 the board found that post-published evidence could only be used to support information that was already derivable from the original application (see also e.g. T 1329/04, T 716/08). For the jurisprudence concerning post-published evidence see also chapter I.D.4.3.3 "Post-published evidence and reliance on a purported technical effect for inventive step ("plausibility")".