Magnetic properties of the amorphous Dy-Fe-B alloy are studied in terms of the correlated-spin-glass approach of Chudnovsky et al.$-— Features predicted by the theory are clearly observed in the experiment. It is shown that the magnetization law may be presented in the form where it is determined by the dimensionless correlation function of structural disorder, C(y), only. The analysis of the magnetization curve allows one to distinguish between different models of disorder in amorphous solids. Experimental data on Dy-Fe-B are in favor of C=exp(-1/2 y 2 ).