The use of solid oxide electrolytes for determining oxygen concentrations in liquid metals has motivated much research of solid electrolyte properties over wide ranges of chemical potential and temperature. A useful scheme for assessing the electrolytic properties of solid electrolytes is that of plotting electronic and electrolytic conduction domains simultaneously with proposed application domains on chemical potential vs. 1/T diagrams. Accordingly, the concept and theoretical origins of conduction domains for solid electrolyte materials are outlined briefly. The origin and usefulness of the concept is discussed with respect to proposed applications of these solid electrolyte materials. Conduction domains for a number of known solid electrolytes are deduced from various conductivity and galvanic cell measurements and the results are presented in the form of conduction domain maps in log space. These maps constitute a survey of present status of knowledge regarding the materials considered. The solid electrolyte materials , , , , , , , and are discussed. Controversial implications and interpretations of conflicting data are pointed out.