The contribution shows how to make a quantitative connection between the high temperature situation of reversible interaction of ionic and electronic defects with the neighboring phases and the situation at low temperatures at which only electronic carriers are reversible. The paper is based on earlier systematic studies of partial equilibria, essentially by K. Sasaki and J. Maier [J. Appl. Phys. 86 (10) (1999) 5422. 5434] and gives a variety of relevant examples. In the cases of higher dimensional defects, the differences between high and low temperature behaviors refer to different kinetic stabilities which are shortly touched upon at the end. (C) 2004 Elsevier B.V. All rights reserved.