Processing or operating environments that utilize direct-current (DC) electric fields provide a driving force for charged point defect migration in ceramic materials. The resulting spatio-temporal redistribution of ionic species leads to time- and field-dependent electrical properties, which can induce material degradation or which can be harnessed for functionality such as resistive switching. The phenomenon of point defect migration is also important in electric-field-assisted sintering, where high temperatures accelerate the kinetics of ion migration, which can in turn lead to thermal runaway and rapid densification. This seminar will discuss the general phenomenon of point defect electromigration, focusing on the effects of sample and electrode boundary conditions on the resulting field-induced stoichiometry gradients. The implications for conductivity evolution will be illuminated, with examples from TiO2, SrTiO3 and Y2O3-stabilized ZrO2 (YSZ). The microstructure evolution during field-assisted sintering behavior of YSZ will be further discussed, comparing the effects of DC and alternating alternating-current (AC) fields.