In T 547/88 inventive step was contested. Although the board had asked the parties to issue a joint protocol stating what tests had to be done and under what conditions, each party had in fact conducted its own experiments and obtained contradictory results. It was therefore not possible for the board, on the basis of these tests, to conclude definitively that no inventive step was involved. The board held that in such a case the patent proprietor should be given the benefit of the doubt with regard to the relevance of the claimed features to the problem to be solved. Moreover, since the prior art did not suggest the subject-matter of the contested claims, that subject-matter implied an inventive step. The patent was therefore maintained.
The burden of proving that the claimed method leads to the advantageous effects mentioned in the patent in suit rests with the patentee. In the absence of any corroborating evidence that these advantageous effects were obtained, the alleged effects are not to be taken into account when assessing inventive step (cf. T 97/00; see also T 1409/04).