In contrast to most other building materials the strength of glass is not a material parameter, but rather a combination of the material treatment and the load position effects. Structural glass elements are produced with heat treatment when compressive residual stresses are created on the surface. The loading position of glass specimen is also significant due to variations in material quality. These two parameters have an effect on the failure stress of glass specimens tested in bending. In this study, the importance of these two parameters is analyzed using a series of experimental data that was previously published. The data is utilized as a source for statistical analysis using the method of sweeping, least square algorithm and finally analysis of variance.