Abstract: In this paper the main sources causing the scatteraing of the experimental results of the material parameters are discussed. They can be divided into two partsj one is the experimental errors which are introduced because of the inaccuracy of experimental equipments, the experimental techniques, etc., and the form of the scattering caused by this source is called external distribution. The other is due to the irregulaiity and inhomc-geneity of the material structure and the randomness of deformation process. The scattering caused by this source is inherent and thej] this form of the scattering is called internal distribution. Obviously the experimental distribution of material parameters combined the two distribution in some way, therefore the .experimental distribution of the material parameters is a sum distribution of the external distribution and the internal distribution. On this view, a general method used to analyse the influence of the experimental errors on the experimental results is presented, and three criteria used to value this influence is defined. An example in which the fracture toughness K1c is analysed shows that this method is reasonable, convenient and effective.

Key words: experimental errors, experimental results, statistical analysis