4.2.3 Test and experimental evidence
In T 702/99 the board made extensive remarks with regard to the probative value of test evidence. It noted that it was essential that comparative tests conducted by a number of persons as evidence for or against qualities such as an improved "feel" of a product (e.g. cosmetics) be made under conditions of maximum objectivity on the part of those conducting the tests. Parties to proceedings should adopt the same standards in the preparation of such test evidence as they should in the preparation of experimental evidence. While the use of independent persons would naturally tend to carry more weight, the use of employees might not be objectionable per se as long as the test conditions were designed to ensure that the employees were not biased by prior knowledge of either the tested products or of their employer's expectation of the test result. The presentation of test evidence also had to be accurate, but the format of the presentation was of secondary importance; a carefully prepared report and/or table might convey as much information as a large number of statements from the testers.
In T 275/11 (bleaching/highlighting composition for hair) in order to demonstrate that the problem was successfully solved, the appellant (patentee) referred to two comparative examples. The board cited T 702/99 and recalled that it was desirable to show that the tests had been carried out under "blind" conditions to avoid any suspicion of bias. The board found that there was no indication of the conditions under which these tests had been conducted. Therefore, any effects referred to by the appellant had to be disregarded.
In T 103/15, on the matter of test reports ("rapports d'essai") filed by the opponent (appellant), the board, with reference to T 702/99, stated that, with respect to the probative value of test evidence, it was important not only to indicate the conditions under which those tests had been conducted, but also to specify the names of the testers and their employers so that the relationship between the testers and the party could be established if necessary. This also applied in cases where the opponent was acting as a straw man on behalf of a company, because then the relationship between that company and the testers could be a factor in deciding on the probative value of the test evidence filed by the straw man. A neutral institute could have been assigned to perform the tests. The appellant had been given the opportunity to provide the relevant information about the authorship of the test report D9 during the oral proceedings, but had refused to do so (see minutes). Lastly, the reasons for not considering document D9 during the first-instance opposition proceedings still applied at the appeal stage. In view of the test report's limited probative value, the board did not take it into account when reviewing the opposition division's decision.
In T 301/94, on the issue of novelty, the board stated that analyses produced by the opponent (Saint-Gobain Emballage) showed that the results obtained by two laboratories (the laboratories of the Institut National du Verre in Belgium and of Saint-Gobain Recherche) for the compositions and the optical properties of the glass bottles all fell within the ranges defined in claim 1 of the patent in suit and that the results of the analyses were in sufficient agreement with each other to be reliable.
In case T 1863/21, concerning an objection under Art. 100(b) EPC (see abstract in chapter II.C.9.3) the appellant (opponent) alleged that the result was not achieved over the entire scope of claims 1 and 2. The appellant's only line of argument was based on a statistical analysis of the results shown in the figure of D15 filed by the patent proprietor. The board observed that statistical significance was not and should not be the sole criterion for considering experimental results, let alone for excluding them from consideration (having analysed the contributions of T 884/06 and T 299/18). A patent didn’t have to fulfil the standards that a peer-reviewed scientific publication might have to comply with. Further the board, with reference to T 2036/21, stated that the deciding body decides in the light of its own conviction, taking into account the evidence available in the proceedings. In proceedings before the EPO, it is thus not a prerequisite to perform a statistical analysis of the results and to determine a specific confidence interval in order to consider a certain piece of evidence convincing, as it is most often required in biomedical research and by health authorities granting marketing authorisations for medicinal products. Statistical significance quantifies the probability that an observed difference in data is not a random occurrence. Hence, the allegation of lack of statistical significance did not in itself prove the hypothesis that there was no difference between groups, or no effect of a treatment (explained in detail in D21, "Retire statistical significance", Nature, 567, 2019, a document that discussed the relevance of statistical significance when reporting on crucial effects in scientific publications).
In T 956/21, the appellant (patent proprietor) raised several objections against the probative value of the experiments reported in D7, questioning the conditions under which the tests in that document had been carried out. The board did not share this view and stated that the minor deviations from the very specific examples of the patent in suit regarding optional, non-essential features could not be considered as a critical deviation which rendered the experiments of D7 irrelevant or non-credible. Contrary to the view of the appellant, it was not required to repeat each and every detail of the examples of the patent in order to challenge sufficiency of disclosure (T 226/85, T 2242/16). Moreover, the board stated the requirement of sufficiency of disclosure implied that the skilled person had to be able to rework the invention over the whole scope and not only when following a very specific and detailed embodiment. The board therefore concluded that although the experiments of D7 deviated slightly from the specific example of the patent, they nevertheless represented the teaching of the patent and were an appropriate repetition of the teaching of the patent which can be considered for assessing sufficiency of disclosure.