3.3.9 Direct and indirect evidence of the state of the art

When evaluating evidence, it is necessary to distinguish between a document which is alleged to be part of the state of the art within the meaning of Art. 54(2) EPC, and a document which is not itself part of the state of the art, but which is submitted as evidence of the state of the art or in substantiation of any other allegation of fact relevant to issues of novelty and inventive step (T 1110/03, OJ 2005, 302). In the first situation, a document is direct evidence of the state of the art; its status as state of the art cannot normally be challenged except on authenticity. In the second situation, a document is also evidence albeit indirect; it provides a basis for an inference about, e.g. the state of the art, common general knowledge in the art, issues of interpretation or technical prejudice etc. – an inference which is subject to challenge as to its plausibility. Only a document of the first kind can be disregarded on the sole ground that it is published after the priority date. Documents of the second kind do not stand or fall by their publication date even on issues of novelty and inventive step. Disregarding indirect evidence would deprive the party of a basic legal procedural right generally recognised in the contracting states and enshrined in Art. 117(1) and Art. 113(1) EPC (T 1110/03 cited in T 1797/09, T 419/12 and recently in T 2508/17, T 504/14, T 1436/17)