In this work evaluation of the effective activation energy Delta h* from the cyclic relaxation experiments is discussed. Particular interest was paid to certain effects and processes that can influence the determined value of Delta h* parameter. The obtained values of parameter Delta h* for As2Se3 glass indicate that both form of the sample and type of applied thermal history influence the determined results. Moreover, the enthalpy relaxation response can be influenced by instabilities of the DSC baseline or by starting crystallization process. However, due to these two effects being not easily separable it was not possible to determine the degrees of their respective influences. (C) 2010 Elsevier B.V. All rights reserved.