Studies of the radioactive properties of fusion devices, including future power stations, rely on calculations of the activation of materials by neutrons produced in fusion reactions. In order for trust to be placed in the results of such calculations it is necessary that the inventory code and the data libraries are validated. This is done by comparing the predictions of the code system with activation measurements made on materials relevant to fusion technology in well-characterised neutron fields. If the ratio of results from Experiment (E) and Calculation (C) is close to 1 then the data are validated. In other cases it may be necessary to change the library data to improve the C/E ratio. As part of the EFDA Fusion Technology Programme the European Activation File (EAF) containing relevant nuclear data library has been developed. This is used as input to the FISPACT code to calculate the activation of irradiated materials. A series of measurements on fusion relevant materials in several complementary neutron fields have been carried out over the last few years. In addition, analyses of measurements performed outside Europe and outside the fusion programme have been undertaken. The results from these measurements are presented in a series of tables, which include the pathways responsible for production of the various radionuclides. The pathways show the reactions that dominate the formation of the measured radionuclides. Knowing the reactions enables the activity measurements to be transformed into effective cross sections (average value of the cross section in the neutron spectrum) which can be compared with the EAF library value calculated in the same spectrum. For the present validation exercise the latest version of the European Activation System (EASY-2007) is used. Analysis of all experimental data enables effective cross sections for four hundred and seventy reactions to be calculated and these are presented in tabular form and also as plots of the C/E ratio. A graph showing the EAF cross section (including the uncertainty estimate) as a function of neutron energy is plotted for each reaction and this also contains all the available experimental differential data (extracted from the international EXFOR database). Using these graphs, an assessment is made to determine if the reaction is validated or if changes to the EAF data should be made, this assessment being quantified as the Quality score for each reaction. These assessments will be used with other information to enable improvements to be made to future EAF libraries.