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 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.