The paper presents a brief analysis of the amplitude-frequency characteristics at a variable frequency of vibration excitation in a specimen and constant temperature and at a constant frequency of vibration excitation and variable temperature. The error of determination of the elastic and inelastic characteristics of high-damping materials is estimated by the resonance methods.Keywords: resonance methods, free damped and forced vibrations, conservative and non-conservative vibrating systems, elastic characteristics, amplitude-independent energy dissipation, resonance curves, logarithmic decrement of vibrations, quality factor of a system, internal friction, high-damping materials.