Abstract: A method and apparatus for training a user to operate an external defibrillator, usable in a therapy or training mode, which includes an energy source; an electrode interface responsive to an electrode arrangeable on a release liner and configured for placement on a subject; and an energy delivery system operable to selectively deliver electrical energy from the energy source to the electrode via the electrode interface. The method includes: when the electrode is coupled to the electrode interface, receiving an input signal from the electrode, prior to placement of the electrode on the subject; based on the input signal, identifying a degree of electrical connectivity along an electrical path including the electrode; based on the determined degree of electrical conductivity, advancing the external defibrillator from a first training state to a second training state; and issuing a training state notification indicating advancement from the first training state to the second training state.