[en] In this paper we make some general comments on the methods used for modelling glasses and use glassy GeSe₂ as an example. We then emphasize recent work on As-Se glasses, including glassy As₂Se₃ and amorphous AsSe. The topology and electronic and vibrational properties of the models are discussed and with their use we infer the microscopic nature of the valence band x-ray photoemission (XPS) signal of g-As₂Se₃ and AsSe. We note that the XPS signal may be interpreted as arising from three distinct subbands with well defined structural origins